Nearly half of former detainees released into the community following November’s NZYQ High Court decision are no longer wearing electronic monitoring ankle bracelets.

The November decision from Australia’s highest court found locking people in immigration detention indefinitely was illegal.

Home Affairs official Michael Thomas made the revelation during a parliamentary committee hearing last night, hours after the government suffered an embarrassing defeat over its latest tranche of migration legislation when the Senate voted to defer the bill.

Responding to a question from opposition home affairs spokesman James Paterson, Thomas said 79 of the 152 people released as a result of the landmark decision were wearing ankle bracelets.

“So 73 are without ankle bracelets,” Paterson replied.

Legislation was passed late last year requiring former detainees to wear monitoring bracelets and abide by curfews as part of conditions that could be reviewed by Immigration Minister Andrew Giles.

Agriculture minister Murray Watt, standing in for Home Affairs Minister Clare O’Neil in the hearing, said the decision to remove an ankle bracelet was based on the advice of a board of experts in the justice system that was formed to deal with the cohort.

Paterson asked how many people who had served sentences for murder no longer had ankle bracelets, however Thomas said he didn’t have the data in front of him.

Australian Border Force Commissioner Michael Outram said the agency had taken previous, similar questions of Paterson’s on notice, but there were complexities in being able to deliver the answers.

“It looks like officers are trying to obfuscate in this committee and not provide information which is in the public interest,” Paterson said, prompting Watt to accuse him of making an “outrageous suggestion” of a cover-up.