Dancing with the Stars

He may be on "Dancing with the Stars," but based on this pic ... it's all about watching Apolo Ohno's massive gun show.

After a kickboxing session on Sunday, the 30-year-old Olympian tweeted a humble pic of himself ... flexing his huge yoked arms.

Doing the Cha-Cha-Cha with Karina Smirnoff does the body good.

The FBI and the LAPD have launched a joint investigation into the suspicious package that was addressed to Bristol Palin at "Dancing with the Stars" this week, TMZ has learned.

Law enforcement sources tell us both agencies are taking the package's threat very seriously and are looking into the possibility that the latest incident is connected to the white powder scare back in 2010.

As we reported, a package containing a white powdery substance was opened on the CBS lot in West Hollywood Wednesday, addressed to Bristol. The package also contained a note, demanding Bristol be removed from the show ... or else.

Someone has it out for Bristol Palin on "Dancing with the Stars" -- TMZ has learned, the suspicious package that was sent to the CBS lot yesterday came with ONE demand ... remove Bristol from the show ... or else.

Sources at CBS tell TMZ, a note was attached to the white-powdery package that read something like, "This is what will happen to you if Bristol Palin stays on [the show]."

The white powder was later determined to be harmless -- but we're told law enforcement is still treating the situation as a credible threat, and is currently investigating the situation.

FYI -- this is the SECOND time Bristol has been targeted by a suspicious letter while appearing on "Dancing with the Stars." The first package was sent when Bristol first appeared on the show in 2010. It also contained a threat.

"Dancing With The Stars" is not even one week into the competition but all-star contestants Pam Anderson and Kirstie Alley are already laying down unique demands behind-the-scenes ... TMZ has learned.

Sources close to the production tell us ... Pam requested her trailer be fully stocked with cases of bottled coconut water called Beyond. Not so crazy, you say? Well the brand is imported from Australia ... and almost impossible to find in the U.S.

Meanwhile, we're told Kirstie REFUSES to eat the craft service food provided by "DWTS" ... and instead chooses to stick to her custom designed diet program Organic Liaison -- which gets hauled in for her daily.

FYI -- Kirstie's rep tells TMZ ... the actress lost 100lbs on her frou-frou diet and is committed to sticking with it ... and adds, "Steve Jobs didn't listen to music on a Zune."

Maksim Chmerkovskiy is adamant ... he NEVER slapped Hope Solo across the face behind the scenes at "Dancing with the Stars" ... despite allegations she made in her new book.

TMZ has learned ... Maksim was absolutely shocked when he heard about the "completely false" story in Hope's book, "Solo: A Memoir of Hope" ... in which the Team USA soccer star claims Maksim pulled a Rick James while trying to put her head in the correct position for a dancing move.

The two were partners on "DWTS" in 2011.

Sources close to Maksim tell us ... he has no idea why Solo would publish such a false and defamatory statement and doesn't know why she would have such ill will towards him ... especially because they've had dinner several times since the show ended.

In fact, Hope JUST tweeted Maksim right before the Olympics, offering him free seats to one of the Team USA soccer games.

"Dancing with the Stars" rump shakers Maksim Chmerkovskiy and Peta Murgatroyd are real pros ... at sucking each other's faces.

The rumored couple hit up XS nightclub in Las Vegas this past weekend and got caught doing a very passionate lip tango. Tens across the board.

Looks like Peta's real prize for winning the DWTS championship with NFL star Donald Driver last week wasn't a mirror ball trophy after all -- it was Maksim.

Tia Carrere's dance moves didn't do her any good last night when she encountered a purse thief in her Las Vegas dressing room following a performance of "Dancing With the Stars: Live in Las Vegas" last night ... TMZ has learned.

According to our sources, Carrere came face-to-face with a guy lurking in her private dressing room after her 10:00 PM show at the Tropicana last night. Rather than scream for help, Carrere tried to give the guy the benefit of the doubt and see what he was doing there ... but he promptly bolted right past her.

Carrere then called out for help, but it was too late ... our sources say the guy made off with her purse, two iPhones, and a wad of cash. We're told another dancer, Anya Garris, had her wallet cleaned out as well.

Maksim and Valentin Chmerkovskiy are used to squeezing into tight spots (cough, leotards) -- but after watching their hysterical attempt at moving furniture ... they should stick to ballroom.

"Dancing with the Stars" pro Maksim Chmerkovskiy -- who was with Melissa Gilbert when she hit her head on the show yesterday -- is strongly insinuating ... "Dancing" producers conspired to overstate the actress' injuries to drum up ratings.

"Dancing" host Tom Bergeron announced at the end of yesterday's show -- Melissa had injured herself during her and Maks' Paso Doble routine (below) ... and was rushed to a nearby hospital.

Melissa later announced on her Twitter she had sustained whiplash and a mild concussion during the performance -- but Maks tells us a different story ... insisting the actress just "bumped her head."

Mark Ballas and his girlfriend got in a 6 minute, alcohol-fueled fight over Mark's unforgivable sin -- smoking a cigarette after promising to quit.

The altercation flared up outside Playhouse nightclub in Hollywood just after midnight Tuesday. We're told Tiffany Dunn was outraged that Mark had broken a deal they had -- she agreed to sell her scooter after injuring herself in an accident, and in return he agreed to quit smoking. But one of Tiffany's friends caught Mark inhaling, blabbed to her and fireworks erupted.

Tiffany screams mid-argument, "You're such a d**k when you drink." For his part, Mark tells Tiff, "You can cry me a river for all I care, and you can swim in it."

Mark tells Tiffany, "You punched me in face 3 times today." She responds, "I was dancing."

Tiffany thinks Mark's fibbing about smoking is a gateway lie: "It makes me wonder what else you lie about. Yeah, exactly, exactly, exactly, what else have you lied to me about?"

At one point ... Mark yanks Tiffany's key chain from her, removes his house key and then hands the chain back. She pushes him and he leaves.

We're told Mark and Tiffany were "hammered," but all ended well. They got a cab together and went home.

Mark Ballas tells TMZ ... he was NOT the target of a Jaleel White meltdown during a "Dancing with the Stars" rehearsal session last week ... despite reports to the contrary.

Mark was leaving Hyde in L.A. last night (the same one Paris, Lindsay and Britney used to party at back in the day) ... when we asked about Jaleel's alleged meltdown ... in which he reportedly screamed at his partner Kym Johnson before going off on Mark.

Gladys Knight is pulling double duty ... 'cause in between training sessions for "Dancing with the Stars," TMZ has learned Knight is also working on a top secret scripted TV show.

Sources close to production tell us ... Knight has been cast to star in a show called "The First Family" ... about a fictional President of the United States who's juggling work with his family life. We're told Gladys is playing the President's mother.

Sources connected to Gladys tell TMZ ... the Motown legend is working extremely hard to handle both gigs ... and producers on both shows are being very flexible to accommodate the star.

We're told the sitcom is already garnering interest from a major network ... which has made it clear they want to rush production to capitalize on Knight's "Dancing" momentum.

Four-time Pro Bowler and children's author Donald Driver isn't taking "Dancing with the Stars" lightly -- sources tell TMZ, the Green Bay wide receiver is working himself to the BONE to crush the competition.

According to sources, Donald's been working non-stop -- practicing with his partner for 5 hours at a time ... then going home and studying dance moves on YouTube.

We're told Donald pays especially close attention to the male pros -- intently studying their moves and their footwork ... just like a football player would study tapes of old games.

According to sources, Donald's goal is to dance at the pro level -- not just the "celebrity" level.

We're told Donald is so focused on being at the top of his game -- he's even keeping his pro partner Peta Murgatroyd on a strict diet.

Gavin Degraw is up for some serious double duty -- he's joining the cast of "Dancing With the Stars" ... but TMZ has learned he will also continue his current U.S. tour.

Multiple "DWTS" sources confirm the "Not Over You" singer has signed on for the new season -- the full cast will be announced on Tuesday morning.

Degraw's taking on a major work load -- the show premieres on March 19th ... but his tour continues through mid April.

We're told Gavin's dancing pro will most likely join him on tour so they can keep practicing -- but none of his tour dates conflict with 'DWTS' airdates.

"Dancing with the Stars" pro Mark Ballas has a MAJOR problem with the "Dance Moms" reality show -- telling TMZ, the angry screaming dance coach is verbally abusing the kids ... and she doesn't know jack squat about dancing.

In case you haven't seen the show ... dance company owner Abby Lee Miller has become famous for berating the children ... once telling a crying little girl, "You save those tears for your pillow, in your room, alone."

Mark tells us, "She's not dancing, she's just yelling at them" ... adding, "I just don't think it's the correct way to teach somebody ... Those kids are 6 years old. They're learning. They're babies ... They need to be treated the correct way."

TMZ has learned the identity of yet another of the contestants for the upcoming season of "Dancing With the Stars" ... the super hot Maria Menounos.

We revealed three cast members yesterday ... "View" host Sherri Sherpherd, "Little House of the Prairie" star Melissa Gilbert, and "Melrose Place" hunk Jack Wagner.

Now we've learned the show has picked the younger and sexier Menounos to join the mix.