Authorities in the Dominican Republic are turning up the heat on the Iowa man who was the last person to see University of Pittsburgh student Sudiksha Konanki before she went missing — grilling him into the early morning hours on Sunday.

Joshua Riibe, a 24-year-old tourist from Iowa, has come under the spotlight, with investigators naming him a 'person of interest.'

Joshua Riibe was interrogated by Dominican Attorney General Yeni Berenice Reynoso and Navy Vice Admiral Agustin Morillo Rodriguez until nearly 3 am on March 16.