Gary Glitter may be detained in Vietnam for another four months while claims that he had sex with under-age girls are investigated by police.
An arrest warrant was issued last week for Gary Glitter
Police official Nguyen Duc Trinh said he was "confident" that a request for extended detention would be granted.
The ex-singer has denied accusations of having sex with two under-age girls, one aged 12, say police in Vietnam.
The two girls in question are said to have had sex with Glitter, 61, at his Vung Tau home. He has not been charged.
An investigation followed the former singer's arrest amid child sex allegations, which his lawyer has called "hearsay".
Lt. Col. Nguyen Duc Trinh, deputy head of the police investigation department in the southern province of Ba Ria-Vung Tau, said initial investigations showed there is evidence that Glitter may have had sex with under-age girls.
The former glam rock star is being held at a prison outside the southern coastal resort of Vung Tau.
In questioning on Monday, he denied having committed "lewd acts" with the girls.
Glitter's newly appointed lawyer, Le Thanh Kinh, said: "What newspapers reported is just hearsay but there has not been any medical certificates to prove there was child sex abuse and how it was conducted."
On Wednesday, authorities in Vietnam decided to extend Glitter's detention at a prison outside Vung Tau by another three days so they can continue their investigation.
But Glitter's lawyer had said he hoped to arrange for his client to be bailed before the terms of the former singer's detention officially expired on Monday.
Vietnamese law stipulates no financial guarantee or bail is needed to obtain release from police custody as long as the person in question can prove the release will not affect any investigation and there is no risk of that person fleeing.
If convicted Glitter - whose real name is Paul Francis Gadd - could be jailed for up to 12 years.
British consular officials saw Glitter in the coastal town of Vung Tau, his home for the past six months.
The 1970s rocker was held on suspicion of "lewd acts" with children after an arrest warrant was issued last week.
He was stopped at Ho Chi Minh City airport on Saturday by an official who recognised him from media coverage.
There are conflicting reports as to whether the second girl had turned 18 - the legal age of consent in Vietnam.
Glitter was found guilty in the UK in 1999 of possessing child pornography and served two months in jail.