ORANJESTAD, Aruba (AP) – Police and a volunteer group from Texas searched a landfill yesterday with the hope of finding clues about what happened to missing US teenager Natalee Holloway.

Crews used a tractor, a bulldozer and infrared equipment at the landfill on the southern part of the island, said Tim Miller, director of the Dickinson-based volunteer Texas EquuSearch.

“There is a good reason we are there, but I can’t disclose that information at all,” Miller told The Associated Press. “This could be a six-hour project or six days.”

Police spokesman Edwin Comemencia declined to say what prompted the search or give any further details.

Reporters were not allowed past the gates of the Parakietenbos landfill, which is on the opposite side of the island from where Holloway disappeared on May 30.

Crews using three water pumps got close to completely draining a pond near the Marriott Hotel, where an eyewitness claimed he saw three young men, including a Dutch youth who has been detained in the case, the night Holloway disappeared.

The witness told investigators that he saw Joran van der Sloot, 17, and two Surinamese brothers driving near the pond on May 30 between 2:30 and 3:00 am – a time they previously told investigators they were already home, said Vinda de Souza, a lawyer for the Holloway Twitty family.

“All we are doing is checking for evidence based on the witness account,” said Comemencia.

When the pond is drained, police planned to search the area, he said.

Extensive searches by Dutch marines, Aruban police, and thousands of volunteers have found no trace of Holloway, who disappeared on the final night of a high school graduation trip to the Dutch Caribbean island.

No one has been charged in the case and van der Sloot is the only person detained as a suspect. The Surinamese brothers, 18-year-old Satish and 21-year-old Deepak Kalpoe, were previously held and released.

Authorities last week took DNA samples from van der Sloot and the two brothers, telling defence attorneys the DNA would be compared to undisclosed material found by investigators.

A judge was expected yesterday to rule on a motion by defence attorneys that would invalidate the samples for any possible trial.

The judge was also expected to rule on a motion by the defence to prevent Aruban investigators from sharing information with the FBI, which has been acting in an advisory role in the case.

The FBI tested strands of blonde hair found on July 17 and concluded they did not come from the missing teenager.

Aruban authorities recently agreed to provide investigation transcripts to the FBI after the country’s prime minister sent a letter to the attorney general’s office urging prosecutors to give the agency all access allowed by Dutch law, which governs the island.