(CBS/AP) Holloway disappeared hours before she was to take a flight home. Police found her passport and packed bags in her hotel room. Extensive land and water searches have failed to turn up any trace of her.
Officials were investigating whether the three new detainees had any connection to two former hotel security guards who have been held in the case since Sunday, Janssen said.
The two ex-guards, Nick John, 30, and Abraham Jones, 28, will remain jailed, at least until a court hearing next week, Janssen said. Neither man has been formally charged.
"It's important that we find the truth," the attorney general said. "We're trying very hard to do our investigation in a professional way."
The Dutch detainee is white, while the two Surinamese men are of Indian origin. The two former security guards are black.
Janssen said the investigation "has nothing to do with color of skin" and social class.
CBS News Correspondent Kelly Cobiella reports that Cynthia Jones came to the courthouse on Wednesday hoping to see her son Abraham for the first time since his arrest. But the closed-door hearings for the suspects were held in their jail cells.
"God knows my son is innocent. My son is innocent," Jones said.
Jones' girlfriend Cynthia Degraph says investigators haven't talked to her about where Jones was the night Holloway disappeared, Cobiella reports.
"We were at the soul beach festival together," she said. "Me, Abraham and a friend Bernadine were all together."
A friend of Jones, 33-year-old Alvin Cornett, a black man, said it was a question of money.
"I've not had a problem with color," he said. "It's a question of rich guys and poor guys."
John and Jones are being investigated on suspicion of murder and capital kidnapping charges, their court-appointed defense lawyers, Noraina Pietersz and Chris Lejuez, have said.
John's lawyer, Noriana Pietersz, said she spoke to her client in jail Thursday.
"I have decided not to demand the immediate release of my client," she said. "We prefer to let the prosecution investigate, confident that my client will be released" by next Wednesday.
Holloway vanished while on a five-day trip with 124 classmates and seven chaperones celebrating their high school graduation.
The night she disappeared, Holloway ate and danced at Carlos' n Charlie's bar and restaurant.
Authorities have not said Holloway was a victim of foul play and have not ruled out any possibilities, including that she may have drowned.
The Aruba government and local tourism organizations have offered a $20,000 reward for information leading to Holloway's rescue, her family and benefactors in Alabama have offered an additional $30,000, and Carlos' n Charlie's donated $5,000.