MANILA, PHILIPPINES (AFP) - Philippine President Benigno Aquino on Friday launched a "Truth Commission" with broad powers to investigate alleged corruption and vote fraud by his predecessor, Gloria Arroyo.

"The process of bringing a necessary closure to the allegations of official wrongdoing and impunity has begun," Aquino said in a statement announcing he had signed an executive order to form the commission.

"It is tasked with investigating and establishing the truth regarding the serious allegations of wrongdoing in the past nine years supposedly involving government officials and their accomplices in the private sector."

The body will look into allegations Arroyo cheated her way to victory in the 2004 presidential election, as well as large-scale corruption cases, Justice Secretary Leila de Lima told reporters.

Among the graft issues to be probed are allegations Arroyo's family and government officials acted improperly in negotiating a 329-million-dollar Internet broadband deal with a Chinese firm, de Lima added.

She said that if Arroyo and others refused to co-operate with the commission, they could be prosecuted for perjury or obstructing justice.

"They can testify or not at their own risk," de Lima said when asked whether Arroyo would have to report to the commission.

Aquino won a landslide election victory in May on a pledge to fight corruption at all levels of society that he said worsened dramatically during Arroyo's nearly 10 years in power.

In the same election Arroyo, who was required by constitutional term limits to step down, won a seat in parliament which her critics alleged was part of a strategy to shield herself from prosecution.

Arroyo's spokeswoman, Elena Bautista, told AFP Friday the former president wanted her legal team to study the basis of the truth commission before commenting on its work.

"It's not just about fairness, but also the legality of the whole thing," Bautista said.

"We would want to see the executive order first." Arroyo has repeatedly denied all allegations of graft and vote rigging.

The commission, which has to finish its work by the end of 2012, will have the power to file or recommend charges.

Hilario Davide, a retired chief justice of the Supreme Court, will head the commission.