Aussie's detention illegal: lawyers

The ongoing detention of an Australian who has spent 18 months in a squalid Jakarta jail is illegal because an Indonesian court botched his extradition hearing, lawyers say.

Robert James McNeice, 44, a dual citizen of Australia and New Zealand, was arrested in Indonesia in August 2008 at Australia's request.

Australia wants him extradited to face charges for allegedly defrauding Aussie Home Loans boss John Symond and his nephew James out of $270,000 in 2003.

At the time of his arrest, authorities said McNeice would have to wait about three months for extradition.

But it took until July last year - 11 months after his arrest - for an Indonesian court to even declare him eligible for extradition.

But McNeice's Indonesian lawyers, Syamsudin Pesilette and Riza Sukri Arief, believe the court's decision is worthless because the judge refused to consider a statement by McNeice.

"The judge's refusal to accept the statement is a violation of the law," the lawyers have written in letters, obtained by AAP, to relevant Indonesian authorities.

"This means the extradition process should be invalidated."

The judge denied their client his right to properly defend himself, rendering his detention since July illegal, they say.

However, under Indonesian law they cannot appeal the court's decision.

Their letters are addressed to the court, to national police, to the justice minister and even President Susilo Bambang Yudhoyono, who will ultimately decide on McNeice's extradition.

Sent in November and December last year, the letters have so far gone unanswered.

Johny Nelson Simanjuntak, from Indonesia's National Commission on Human Rights, agrees McNeice has been wronged.

"McNeice's treatment has definitely violated the law, Indonesian law at least, as well as his human rights," he said.

"He's been detained much longer than he's supposed to be.

"He's been treated unjustly and his rights have been robbed."

McNeice, who has pleaded with Prime Minister Kevin Rudd to intervene in his case, has now been waiting seven months for Dr Yudhoyono to formally approve his extradition.