A registered sex offender who was freed from indefinite detention has been arrested in Victoria, throwing fuel onto the political fire over the release of some 150 immigrants.

Victoria Police confirmed the 33-year-old was arrested after allegedly breaching his reporting obligations that come with being a registered sex offender.

The man was alleged to have previously been the ringleader of a prostitution ring and preyed on children in state care, shadow attorney-general Michaelia Cash said under parliamentary privilege.

Several media outlets have named the man and said he had allegedly breached his conditions by making contact with minors. He was arrested in Dandenong, in Melbourne’s outer-south east.

He is the third ex-detainee to have allegedly committed an offence after two other men were also arrested.

Afghan refugee Aliyawar Yawari, 65, fronted court in Adelaide on Monday charged with two counts of indecent assault in relation to an alleged incident involving a woman at a hotel.

A second detainee, 45, was stopped by police in Sydney on Saturday and charged with drug possession. NSW Police alleged he was carrying cannabis in resealable bags.

The opposition seized on the arrests and accused of the government of not having legislation prepared to keep the worst offenders behind bars before the High Court handed down its decision to release detainees.

The ordeal has been branded “a catastrophic failure”.

“The Albanese government has failed their number one duty, which is to keep the Australian community safe,” opposition immigration spokesman Dan Tehan told Seven’s Sunrise program on Tuesday.

He called for ministerial heads to roll.

Tehan also accused the government of failing to adequately prepare for the possibility of the High Court ruling that indefinite immigration detention was illegal.

Attorney-General Mark Dreyfus offered the opposition a private briefing where it could be shown the legal advice from the solicitor-general and Australian Government Solicitor.

The advice refers to the court’s ruling that the detainees must be released and what the government’s power was to detain those covered by the decision.

It will not be released publicly to protect legal professional privilege.

The government’s response had always been in accordance with the law, Dreyfus said in a statement tabled in the Senate.

“The High Court determines the meaning of the Australian constitution – not politicians,” he said.

The court made a decision that applied to people held in immigration detention in the same circumstances as the original complainant, NZYQ.

“As a result of the High Court’s decision, the continued detention of any NZYQ-affected person would be unlawful,” Dreyfus wrote.

“There is no legal basis on which the government can delay releasing the person until, for example, a court orders the person’s release.”

Any delay could open the Commonwealth up to legal action over false imprisonment, a spokesman for Dreyfus said.

“The Albanese government cannot and would not ask, let alone direct, Commonwealth officials to break the law,” the spokesperson said.

The opposition has consistently argued for law changes to keep the worst offenders locked up as it works with the government to introduce a preventative detention regime to get some of the cohort back behind bars.

But the preventative detention regime could not apply to the whole cohort, Dreyfus said.

It could be applied only in a non-punitive manner, such as for the protection of the Australian community from an unacceptable risk of grave or serious harm, he said.

Australian Lawyers Alliance spokesman Greg Barns said the charged detainees were entitled to the presumption of innocence.

“Every day of the week ex-prisoners, unfortunately, commit further offences and, depending on the allegations and their circumstances, they are not necessarily detained but are granted bail,” he said.

The federal government will introduce laws to establish the regime on Wednesday.

The exact number of released detainees the preventative detention orders would apply to is not known.

The Coalition would likely back the laws, Opposition Leader Peter Dutton said.

-with AAP