The last person authorities believe may have seen Sudiksha Konanki, the 20-year-old University of Pittsburgh student who vanished while on a spring break trip in the Dominican Republic, was back on the beach — this time with investigators.

Joshua Riibe is believed to be the last person to have seen University of Pittsburgh student Sudiksha Konanki before she went missing nearly 10 days ago.

An American linked to the disappearance of a University of Pittsburgh student was spotted by NBC News with investigators, his father and his attorney on a beach in Punta Cana early Sunday. Joshua Riibe was seen pointing toward the sea while a group of security officials kept people away from the area.

Sudiksha Konanki, a 20-year-old Indian-American student, vanished while on a spring break trip to Punta Cana, Dominican Republic.

The case of missing Indian-origin student Sudiksha Konanki continues to unravel. The last person to see the 20-year-old, who disappeared in the Dominican Republic, was Joshua Riibe. Authorities have declared the 22-year-old man a ‘person of interest’ and confiscated his passport;