Andrew Burrell, Manila – A United Nations-backed tribunal yesterday issued an arrest warrant for Indonesia's former military chief Wiranto, in a move that could become a wildcard issue in next month's presidential election campaign.

Mr Wiranto, who is running for president, could be arrested for war crimes if he travels outside Indonesia, which would prove an embarrassment should he win the top job at the July 5 election.

However, he cannot be arrested if he remains in Indonesia, as Jakarta has refused to extradite him over allegations he was ultimately responsible for the murder, deportation and persecution that took place in East Timor in 1999.

Mr Wiranto's aides could not be reached for comment last night, but he has long denied any wrongdoing and claimed the accusations of human rights abuses were drummed up by the international media.

It is unclear how the warrant will affect Mr Wiranto's high-profile campaign as the presidential candidate of the Golkar party, which last week was declared the winner of the April 5 parliamentary election.

However, his current lowly ranking in opinion polls would probably improve if the warrant inspired sympathy among nationalist voters who may view the tribunal's decision as foreign interference in Indonesia's legal system.

Conversely, the allegations could be used against him during the campaign by his political opponents, as well as foreign and local human rights groups.

This may benefit the presidential frontrunner, Susilo Bambang Yudhoyono, another former general who has a cleaner reputation than Mr Wiranto.

UN prosecutors in Dili allege that as military chief, Mr Wiranto held ultimate command responsibility for the military-backed militia violence that left 1500 people dead during East Timor's separation from Indonesia.

Last month, prosecutors set out their case against Mr Wiranto for the first time, publishing a thorough account of the evidence as part of their push for an Interpol arrest warrant.

"The evidence proves that the accused, as the highest military and police official in Indonesia, exercised effective control over the militias who perpetrated many of the crimes," the UN document said.

The UN's deputy general prosecutor in Dili, Nicholas Koumjian, said yesterday the warrant was an important step in attempts to bring to justice those responsible for the violence in East Timor.

"It sends a message that the victims have not been forgotten and that the international community will not tolerate impunity for those responsible for crimes against humanity, whoever they are."

Mr Wiranto is one of more than 83 people indicted by the UN-funded tribunal. Fifty have been convicted – mostly East Timorese militiamen used as auxiliaries by the Indonesian troops during the rampage.

A spokesman for the Indonesian government, Marty Natalegawa, said last night Jakarta would not extradite Mr Wiranto because the warrant had not been issued by an official UN tribunal.

"From Indonesia's perspective it is purely an East Timor internal affair – it is not a UN arrest warrant and we are not bound to it," he said "We will not surrender an Indonesian citizen to another country, based on a legal process we do not acknowledge."

The warrant was issued as Mr Wiranto confirmed yesterday he would contest the election with an Islamic figure, Solahuddin Wahid, as his vice-presidential running mate.

It is a noteworthy choice because Mr Wahid, a brother of former president Abdurrahman Wahid, is the deputy chairman of Indonesia's national human rights commission.

The other main contenders in the presidential race include President Megawati Soekarnoputri and parliamentary speaker Amien Rais.