Person of interest in case of missing university student speaks out for first time

An American vacationing in the Caribbean at the time of Sudiksha Konanki's disappearance has broken his silence after footage showed him with the 20-year-old in the early hours of the last morning she was seen.

The University of Pittsburgh, Pennsylvania, student vanished on March 6 while on a spring break vacation in Punta Cana, Dominican Republic, with 22-year-old Joshua Riibe captured on CCTV walking arm-in-arm with her shortly after 4.00am.

Riibe has been made a 'person of interest' in the case by Loudoun County Sheriff's Office, and his family have previously spoken out about the 'irregular conditions' he has been placed under - despite not being charged or even accused of a crime.

Riibe is not considered a suspect, but 'he may have been the last one to see her', police say.

Riibe, of Rock Rapids, Iowa, was also vacationing in the Caribbean beauty spot, having taken a break from his studies as a senior at St. Cloud State University in Minnesota.

Riibe has now spoken to a NBC news reporter at the resort where Sudiksha had been staying.

When asked about the case, he replied: "I’m just trying to help them out."

Before adding: "The ocean is a dangerous place."

Sudiksha Konanki was last seen on March 6 in the Dominican Republic (Law and Crime Network)

Meanwhile, the law firm representing the college student told NBC News in an email on Saturday (March 15): "[Riibe] has been confined to the hotel since the investigation began. He is permanently escorted by the police anywhere he goes. So no, he is not free to leave."

In a statement issued to WTAE, his parents said: "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.

"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.

A huge search is underway for the student (Defensa Civil Dominicana)

"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."

They also told CBS News they hope Sudiksha is 'found as soon as possible'.

Surveillance footage shows Sudiksha heading to the beach with a group of friends - including Riibe - at around 4.00am following a night of partying.

Authorities believe they have found her clothes on a sun bed on the Dominican Republic beach where police think she was going for a swim, reports ABC News.