Updated

A judge on Saturday ordered the teenage son of a prominent justice official and two of his friends to stay in jail for at least another week while investigators search for clues in the disappearance of a young Alabama woman.

A disc jockey on an Aruban tourist party boat who also has been detained in the case was to appear before a judge Monday, the attorney general's spokeswoman Mariaine Croes said as the search for 18-year-old Natalee Holloway (search) neared the end of three weeks.

Under Dutch law, which Aruba follows as a Dutch protectorate, authorities can detain individuals for up to 116 days without filing formal charges. A judge must review the case after the first 10 days, and then periodically after that.

Holloway, of Mountain Brook, Ala., disappeared in the early hours of May 30, the last day of a five-day vacation with 124 other students to celebrate their high school graduation.

She has not been found, but investigators refused to say if they thought Holloway was dead. Her mother, Beth Holloway Twitty (search), has said she will continue to believe Holloway is alive until she has proof otherwise.

The judge on Saturday extended the detention of Joran van der Sloot (search), 17, and brothers, Deepak Kalpoe, 21, and Satish Kalpoe, 18, for eight days, Croes said.

A fourth man who was detained Friday was identified by his boss as Steve Gregory Croes, a 26-year-old disc jockey on a privately owned party boat. He was arrested early Friday, a day after being contacted by police and giving them a statement, the boat's owner Marcus Wiggins told The Associated Press. The detainee is not related to the attorney general's spokeswoman.

Van der Sloot is the son of Paul van der Sloot (search), of the Netherlands, who is training to be a judge in Aruba. Holloway Twitty, 44, has insisted that he and the Kalpoe brothers hold the key to the investigation and she wants authorities to pressure the young men harder to tell the truth.

In Alabama, a friend of Holloway's family said the young woman's relatives, not Aruban police, first identified and located Joran and the Kalpoe brothers — less than a day after she disappeared.

"She had been missing less than 24 hours and we had all three names and addresses, so it's just disappointing that they (authorities) weren't able to move faster," Jody Bearman, who organized the graduation trip and went to Aruba to help in the search, told The Associated Press on Friday.

Holloway Twitty said if significant progress is not made soon in the case, she may start to believe that authorities are protecting the detainees. Aruban authorities have said they are pursuing all leads and protecting no one.

On Friday, a judge ruled on a petition from the elder van der Sloot to visit his son, whom he has not been allowed to see since Joran was detained on June 9, and from the Kalpoes' attorneys requesting to see any evidence prosecutors may have gathered. Both Croes and a court secretary refused to reveal the rulings. Defense attorneys did not return calls seeking comment.

It was not clear how the disc jockey might be connected to the other detainees. He told Wiggins that he knew one of the Kalpoe brothers because he went to the same Internet cafe, Wiggins said.