Joran van der Sloot, Deepak Kalpoe and Satish Kalpoe were arrested on 9 June 2005 on suspicion of kidnapping and murdering Holloway. The three youngsters had been named early on in the hunt for Holloway as they had been identified with her outside the Carlos 'n Charlie's club, the last known sighting of the teenager before she vanished.
Police Commissioner Gerold Dompig, who took over from Jan van der Straten following his retirement in mid-2005, stated that the three had been suspects from the start and they had been under police surveillance via telephone wire taps and the monitoring of their emails.
On 17 June 2005, a fourth person, Steve Gregory Croes, was also arrested based on information given by one of the other three detainees and on 22 June 2005 police also arrested Paulus van der Sloot, Joran van der Sloot's father. Both Paulus van der Sloot and Croes were released a few days later.
The stories given by the three detained suspects kept changing as to what had happened to Holloway. All three alibis matched in so far as saying that van der Sloot and Holloway were dropped off at the Marriott Hotel beach near the fishermen's huts. However, van der Sloot stated that he did not harm Holloway in any way and had merely left her on the beach. Van der Sloot's account was continuously altered and later, during his interrogation, he panicked and changed his story to say that in fact he had been dropped off at home and Holloway was driven off by the Kalpoe brothers.
Dompig immediately disbelieved this new version of events on the basis that Van der Sloot had started to worry that the Kalpoe brothers were trying to point the finger in his direction and in return he thought he would place the blame on them.
On 4 July 2005, Deepak and Satish Kalpoe were released from custody following hearings before a judge, but Joran van der Sloot was held for a further 60 days.
The Kalpoe brothers were rearrested on 26 August 2005 along with another new suspect, Freddy Arambatzis, 21, who was suspected of having physical contact with an underage girl; an incident which had allegedly occurred before Holloway disappeared and in which Arambatzis's friends van der Sloot and the Kalpoe brothers had apparently been involved. Van der Sloot's mother, Anita, commented, "It's a desperate attempt to get the boys to talk”.
On 3 September 2005, all of the detained suspects were released by a judge and subsequently, on 14 September 2005, all restrictions on them were removed by the Combined Appeals Court of the Netherlands Antilles and Aruba. They had not found enough substantial evidence to convict any of the suspects.
Between April and May 2006, three more people were arrested on suspicion of being involved in Holloway's disappearance but despite being extensively questioned, all of them were also released without charge.
By 2006, the Aruban authorities had exhausted their leads in the case and requested that the Netherlands instead took over the investigation. The Dutch National Police began work afresh on the case in September 2006 and a new search was launched at the van der Sloot family home in April 2007. A month later, police turned their attentions to the other original prime suspects, the Kalpoe brothers, and on 21 November 2007, the three original suspects in the case, the Kalpoe brothers and van der Sloot, were all rearrested. All three were released by December 2007, with the court determining that there was still not enough evidence to conclude that the suspects had anything to do with Holloway's disappearance.
On 18 December 2007, Holloway's case was officially declared closed. In total, ten people were arrested on suspicion of being involved in Holloway's disappearance but no charges were filed and no one remains in custody.