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.

St. Cloud State senior Joshua Riibe has remained in his hotel room under police surveillance when not questioned at the police station, his parents said.

Sudiksha Konanki, a University of Pittsburgh student, went missing in Punta Cana, Dominican Republic on March 6. She was on spring break with friends and was last seen on the beach near her hotel at around 4:50 a.m. The F.B.I. joined the investigation into her disappearance and U.S. detectives have been sent to the Dominican Republic.