Kris Humphries Ex Flame: Voicemail: 'I Have Way More S**t I Can Put Out!'

Kris Humphries' ex-flame Myla Sinanaj threatened to release sordid details about her relationship with Kris ... and TMZ has the voicemail.

Sources say ... after photos of Myla and Kris began leaking, Kris broke off all contact with her. Myla became enraged after trying in vain 17 times to reach Kris and then called one of his friends.

Myla left a message, demanding that Kris stop stonewalling her and return her calls.

Myla says, "If he's going to play me like that, I have way more sh*t I can put out."

The voicemail does not show alleged extortion on Sinanaj's part, as Humphries claims. Nonetheless, we're told Kris' lawyers gave it to the FBI when they made their extortion complaint.

Myla's lawyer, Joe Tacopina, tells TMZ, there was no evidence of extortion and unless Kris and his lawyer apologize immediately they will both be on the receiving end of a defamation suit.

Tacopina says Myla was indeed angry when she read that Kris was calling her a "booty call." Tacopina says hundreds of emails and text messages show Myla and Kris were in a "substantial relationship," with Myla meeting Kris' parents, helping his sister shop for furniture for her new apartment and spending many evenings together at home cooking meals.