Australian authorities, joined on Thursday by British police said they might try to extend the detention of an Indian doctor held in connection with the plot to detonate car bombs in London and Scotland.
A senior British counter-terrorism officer had arrived in Brisbane to help police question Mohamed Haneef, the 27-year-old doctor who was detained trying to leave Australia on Monday.
<b1>But with only 12 hours to interrogate Haneef beyond a 48-hour warrant expiring on Thursday night, Australian Federal Police said authorities could ask a judge for more time, using the country's new tough anti-terrorism laws.
"We could ask for more time, but we would need to provide a magistrate with good reasons why," an AFP spokeswoman said.
Haneef is one of eight people arrested over the car bomb plot who are doctors or have medical links, and the only one held outside Britain.
His family in India has said he is innocent and brother Mohammed Shuaib said Haneef planned to visit only see his wife Firdaus Arshiya, who recently gave birth in Bangalore.
"His character is like a mirror -- clean," sister Sumaiyaa Tabassum told The Australian newspaper.
Authorities at the Gold Coast Hospital where Haneef worked confirmed on Wednesday that he was given emergency leave on Monday to visit his wife and baby daughter.
Police are examining Haneef's laptop computer and a sim card mobile phone device he left with one of the British bomb suspects.
A former Australian High Court chief justice on Thursday criticised the 2004 anti-terrorism laws used for the first time to detain Haneef and said they may appear to be targeting Muslims.
"The terrorism legislation and the actions to be taken under it do impair the freedoms and immunities which the common law protects," said Gerard Brennan, formerly Australia's most senior judge.
Security analysts have speculated the government may not wish to extend Haneef's detention for fear of provoking civil liberties complaints.
But Australia's Attorney-General Philip Ruddock said the contentious laws could even be strengthened to extend the amount of time a person could be detained without charge.
"There may well be some finessing of some issues," Ruddock told Australian radio.
Haneef cannot be extradited to Britain unless he is charged.
AFP Commissioner Mick Keelty earlier this week said the evidence against Haneef went further than mobile phone cards and said a considerable amount of material had been seized during a series of searches on his flat in southern Queensland state.