PUNTA CANA, Dominican Republic — The passport of Joshua Riibes, an American linked to the disappearance of a University of Pittsburgh student, has been confiscated by Dominican authorities as part of an ongoing investigation, his attorneys told NBC News.

Riibe might have been the last person to see Sudiksha Konanki, a 20-year-old Pittsburgh junior who went to Punta Cana on March 3 with five female friends for spring break. She was last seen around 4:15 a.m. on March 6 after going to the beach with friends.

Speaking exclusively to NBC News briefly at the resort where Konanki had been staying before her disappearance, Riibe said, “I’m just trying to help them out,” adding: “The ocean is a dangerous place.”

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,” his law firm told NBC News on Saturday.

The Dominican Republic’s national police did not immediately respond to NBC News’ request for comment.