Fiji police say they need more evidence that the deposed prime minister, Laisenia Qarase, committed treason as alleged by the military.
The Fijilive news website quotes the head of police criminal investigations, Josaia Rasiga, as saying detectives have returned from Mr Qarase's home island, Vanuabalavu, after interviewing him.
Mr Rasiga says further investigation is needed before they forward their file to the director of public prosecutions to determine if charges should be laid.
The military has accused Mr Qarase of betraying his country by asking Australia and New Zealand to send troops to invade Fiji during the overthrow of his government last year.
Mr Qarase says he wants his lawyer to be present at further police interviews but Tevita Fa says he will not be able to travel to Vanuabalavu due to his heavy workload.
Meanwhile, Mr Fa says he intends to mount a court challenge to the military's decision to confine Mr Qarase to his home island since the December 5th takeover.