Police in Antigua today said three people remain in custody in connection with the murders of newly-wed British couple Ben and Catherine Mullany.
It follows the arrest of eight people late last week, some of whom were considered "prime suspects" in the investigation.
In a statement, police said some of the arrests had led to charges for drugs-related offences unconnected to the double murder.
The couple, from Pontardawe, in the south of Wales, were shot in the head in their cottage at the Cocos Hotel and Resort on July 27 - the last day of their honeymoon.
Two women, aged 32 and 22, have already been charged and appeared before magistrates in the island's capital, St John's, last Thursday, but police have been reluctant to disclose details of the charges. However, it is understood they relate to property stolen from the Mullanys' holiday cottage.
Today's statement said: "A number of individuals were detained and questioned this week as a result of a proactive police operation.
"Consequently, some have been charged with drug related offences unconnected to the Mullanys' murder. At this stage, we are not in a position to disclose any further information regarding these individuals.
"So far as the two females arrested and charged last week, they are still remanded in custody at Her Majesty's Prison and are linked to the other three persons presently in police custody."
Local police are continuing to work with a team from Scotland Yard who have flown out to assist with the investigation.
Mrs Mullany, 31, a doctor, died instantly in the attack. Her husband, a trainee physiotherapist, also 31, died in hospital in Swansea after he was flown home in a coma.
They were buried in a private ceremony on Wednesday, just one month after saying their wedding vows. It is believed the ceremony took place at St John the Evangelist Church, in Cilybebyll, where they married.
Their families are planning another memorial service so relatives, friends and colleagues can pay their respects. They requested no flowers and said details of a memorial fund would be announced in due course.
Swansea coroner Philip Rogers had released the bodies for burial when he opened and adjourned an inquest into the couple's deaths on Tuesday.