Joshua Riibe Detained in Puerto Rico After Release From Dominican Republic

Joshua Riibe -- the college student who was declared a person of interest in the disappearance of University of Pittsburgh student Sudiksha Konanki -- was detained in Puerto Rico after he was cleared to leave the Dominican Republic.

Riibe -- who has not been charged in Konanki's suspected drowning -- got held up at the airport in Puerto Rico Wednesday because his brand new U.S. passport wasn't properly stamped, NotiCentro reports.

The 22-year-old was issued a replacement passport from the U.S. consulate in the D.R. after local law enforcement reportedly refused to give his original passport back -- despite a Dominican judge ruling he was allowed to go free after being subject to police surveillance due to his connection to Konanki.

NotiCentro cameras captured Riibe's father, Albert Riibe, in a state of frustration at the airport after he was separated from Joshua. He was seen yelling to Joshua down a hall ... "Ask for your lawyer!"

He also pled with reporters to let him and his son be, explaining ... "I'm just a dad, who had his son taken away, and I don’t understand. We just spent two weeks trying to stay together, and now … I don’t understand." It's unclear how long Joshua was held.

Joshua, a student at St. Cloud State University in Minnesota, was named a person of interest after surveillance video recorded him as the last person seen with Konanki before she disappeared.

The pair were seen walking toward the beach at Riu República Hotel in Punta Cana early in the morning of March 6. Surveillance video also shows both Konanki and Riibe vomiting at the hotel's bar shortly before the time of her disappearance -- although they were not mingling at the time.

Riibe told law enforcement they were in the water together and nearly got swept away by a giant wave ... but he was able to pull them both to shore. He remembers last seeing her walking knee-deep in the water to grab her belongings.

Her clothes were later found draped over a beach chair during the investigation.