The parents of the Minnesota college student identified as a person of interest in the disappearance of University of Pittsburgh student Sudiksha Konanki said their son has been detained “under irregular conditions” – as sources said authorities in the Dominican Republic pledged to intensify interrogations.

Albert and Tina Riibe are pleading for justice and transparency after learning that their son, Joshua Riibe, 22, who is believed to be the last person to see the missing 20-year-old, has been repeatedly questioned by police, often for long hours, since Konanki vanished on a beach in the Dominican Republic on March 6.

“Despite his full willingness to cooperate, Josh has been detained under irregular conditions and subjected to extensive questioning without the presence of official translators or legal counsel until Wednesday, March 12,” the worried parents said in a statement, WTAE reported.

“He has remained in his hotel room under police surveillance and has been repeatedly taken to the police station since March 6, where he has been interrogated for long hours. This situation has raised serious concern within his family, which has led us to retain legal counsel to initiate legal actions ensuring his safety and the protection of his rights throughout this process.”

Riibe, who was named a person of interest, but not a suspect, is expected to remain detained by local authorities as the search continues – and sources with knowledge of the case indicated Friday that a high-ranking member of the Public Prosecutor’s Office is expected to intensify interrogations.

The Iowa resident had traveled to the RIU Hotel & Resort in Punta Cana for spring break – the same five-star resort where Konanki was staying with a group of friends.

Surveillance footage of the night Konanki went missing shows her walking with Riibe near the beach around 4:15 a.m. At one point, the pair can be seen holding hands as Konanki’s spring-break friends from college walk nearby.

Konanki and several friends were on the beach before most of the group called it a night and headed back to their hotel, leaving the young woman on the sand along with her male companion, according to Dominican media. 

Riibe, a former wrestler and football player at Central Lyon High School in Rock Rapids, has since provided police with several conflicting accounts of what happened after the two were alone on the beach.

He last told police he saved Konanki from the rough Caribbean waters before losing her in the darkness of night, according to a transcript obtained by Dominican Republic’s Noticas Sin.

He said he managed to get the two of them back to a safe spot in the water closer to the beach.

Here is the latest information on missing Pitt student, Sudiksha Konanki:

• University of Pittsburgh student Sudiksha Konanki was on spring break in Punta Cana prior to her disappearance.
• Konanki, from Virginia, and her pals went onto the beach from a disco at the Riu Republica Hotel early in the morning following a power outage.
• She was last seen with Joshua Steven Riibe from Iowa, who was named “a person of interest.”
• Sheriff Mike Chapman of Konanki’s hometown in Loudoun County, Virginia, has previously said it is too early to determine if she had drowned.
• Konanki’s parents asked Dominican Republic officials to declare her dead despite her body not being recovered.
• Riibe was officially cleared of wrongdoing Konanki’s disappearance.

He recalled hearing Konanki saying she was going to get her belongings as the water had pushed them away from the area they had set up.

The 20-year-old was still in knee-deep water, walking at an “angle.”

“The last time I saw her, I asked her if she was OK,” Riibe said. “I didn’t hear her answer because I started vomiting all the sea water I had swallowed.”

The St. Cloud State University senior has since refused to answer several key questions about the case, giving the same 14-word response to each inquiry: “My lawyers advise me not to answer that question and I follow their advice.”

Konanki, a Virginia resident, was reported missing around 4 p.m. March 6 by the group of friends with whom she had traveled to the Caribbean nation.

Officials initially believed her disappearance was a drowning, but announced Wednesday that they hadn’t ruled out foul play.

Riibe’s recounting appears to line up with an investigative police report that stated the Indian national was hit by a large wave while swimming at night, according to the report cited by ABC.

The Loudoun County Sheriff’s Office, the law enforcement agency in Konanki’s hometown in Virginia, also named Riibe as a person of interest but cautioned that he was not a suspect.

“We recognize that this is a complex and painful situation for all parties involved, and we trust that the investigation will be conducted with transparency and justice,” Riibe’s parents said in their statement.

“Our only interest is that due process be respected and that actions be taken with the fairness that the situation requires.”

Additional reporting by Jorge Fitz-Gibbon