Selangor Criminal Investigation Department chief Hasnan Hassan said the man and four others, including two Singaporean women, were held captive when they visited the unit at 4pm.

'According to the Singaporean women, they were forced to become 'drug mules' by four Nigerian men who abducted them,' Bernama reported him as saying.

The man, a college student in his 30s, was found naked on the ground floor of the condominium at about 8.30pm.

He was earlier forced to strip and tied up with the other captives, but managed to untie himself.

However, he fell to his death while trying to escape.

Mr Hasnan said the police were looking for two men who were also stripped and tied up in the incident.

Malaysian police have also obtained a three-day detention order against the two Singaporean women who will be held for questioning until today.

They are in police custody at the district police headquarters for Subang Jaya, Selangor.

According to a police investigating officer, who requested anonymity, the two Singaporean women are aged 27 and 28.

'The two Singaporeans have given us an initial statement but we need to get more details from them because their statements are sketchy,' the investigating officer told The Straits Times on Tuesday.

Police said the two women told them that they entered Malaysia as tourists.