Two white-uniformed investigators from Holland on Wednesday also entered the yellow-beige home, which includes an attached apartment where the young man lives, carrying suitcases. They later returned the suitcases to their white, unmarked car.
CBS News Correspondent Kelly Cobiella reports that if the searches in the past two days at the home and a beach have turned up more pieces to fill in the puzzle of Holloways's disappearance, investigators are keeping the details to themselves.
"I can just say because of the investigation, they thought it was a wise move to go there again and again perform a technical investigation," said Mariaine Croes, a spokeswoman for Attorney General Caren Janssen, on CBS News' The Early Show.
Earlier, the Dutch official, Paul van der Sloot, asked a judge for permission to see his 17-year-old son, Joran, who remains in police custody with two other young men in the May 30 disappearance of Holloway, an 18-year-old honors student from Alabama.
Lawyers for the three — Joran van der Sloot and brothers Deepak Kalpoe, 21, and Satish Kalpoe, 18 — also asked a judge to see the evidence against their clients.
The attorney general's office said in a statement the court would rule Thursday on both petitions.
That statement also said a helicopter would "conduct technical investigations" across the island Wednesday night. Calls to authorities seeking further details were not immediately returned.
Croes confirmed to Early Show co-anchor Rene Syler that authorities used thermal sensing equipment to search specific areas last night, but she said that the search did not yield anything.
Holloway was celebrating her graduation from Mountain Brook, Ala., High School with 124 other students and seven chaperones when she vanished. Her U.S. passport and packed bags were found in her room.
Numerous searches by authorities, volunteer islanders and tourists have led nowhere. No one has been charged in the case.
On Tuesday, FBI agents and officers from the Miami-Dade police department used German Shepherds to search a beachside mangrove swamp next to the Marriott Hotel after a former detainee in the case said the three young men may have lied to police about where they took Holloway. The area, known as Malmok beach, is a popular nighttime spot for lovers.