An anti-corruption body in the Philippines has filed criminal charges against ex-President Benigno Aquino for mishandling a police raid that left 44 commandos dead in 2015.

The Office of the Ombudsman on Wednesday charged Aquino with fraud and usurpation of official functions for approving the operation to arrest a suspected bomb-maker in Mamasapano, Mindanao.

Aquino had allowed suspended police chief Alan Purisima to lead the botched raid in January 2015 despite being already dismissed from office over a fraud case.

During the operation, police commandos suffered heavy casualties after being surrounded by a large number of fighters and met with intense gunfire.

"Just like most Philippine presidents, Aquino preferred working with close friends and allies," Al Jazeera's Jamela Alindogan, reporting from Manila, said.

"Purisima was present at a meeting when the Mamasapano raid was planned, thereby bypassing the hierarchy of the Philippine military and the battalion commanders on the ground," she added.

Alindogan noted, however, that the case "was bailable by just about $1,000, so it is unlikely that the former president will actually go to jail".

The deaths of the police officers shocked the Philippines and also contributed to the stalling of a peace process with the Moro Islamic Liberation Front (MILF), an armed group negotiating with the government for greater autonomy for the Moro people in the south.

"Until now that peace process remains pending," said Alindogan.

"The raid happened at MILF territory," she added. "Gore videos of how the special action forces were killed gad actually turned public opinion against the MILF."

'Grave error'

Aquino, who served from 2010 until 2016, had previously said he did not directly take part in the planning and execution of the raid. He had also said he was only briefed broadly on the plan and there was no need for him to approve it.

Yet, his decision "was a major error ... that had very grave consequences", said Alindogan.

"It weakened his leadership and popularity, and cost the disintegration of the Liberal Party that eventually led, in a way, to the victory of President Rodrigo Duterte," she added.

"It also, in many ways, caused a rift between the Philippine military and the country's national police. A senate inquiry was live on television, and helped the public to see just how reckless this decision was."