MANILA - High-profile inmate Jaybee Sebastian, represented by his wife Roxanne, is set to file a complaint against Senator Leila de Lima before the Office of the Ombudsman for "gross inexcusable negligence" and violations of the anti-torture law, his lawyer said.

Sebastian's camp was supposed to file the complaint on Wednesday afternoon, but was instructed by the Office of the Ombudsman to return the following day as "the complainant needs to [personally] appear so that an oath may be administered."

Sebastian decided to sue the former Justice secretary after she publicly announced that he used to be a government informant.

"Because of De Lima's revelation that Sebastian was an asset, inmates in Building 14 [of the New Bilibid Prison] were enraged, thus his purported killing on September 28," Sebastian's legal counsel Eduardo Arriba said.

Among the detainees in the Building 14 of the NBP are the 'Bilibid 19' or the high-profile inmates who enjoyed VIP treatment until the government uncovered their luxurious lifestyles in the national penitentiary in 2014.

Under the Anti-graft and Corrupt Practices Act, public officials who cause undue injury to a party in the discharge of his function through evident bad faith and gross inexcusable negligence should be penalized, Arriba explained to reporters.

Arriba considered De Lima's revelation and prior decision to move Sebastian and the Bilibid 19 in a similar detention facility as a gross, inexcusable negligence that placed his client's life on the line.

"Under the law, Sebastian being a government asset should not be disclosed as his security will be at stake... It's public knowledge that he was the target of the Bilibid bombing," Arriba said.

Violations of the Anti-torture Act were committed when Sebastian was placed in isolation from October 2014 to January 2016 after he was transferred to the national penitentiary's Building 14, he said.

"Placing Sebastian in a solitary confinement, locking him up 24/7, not allowing anyone to visit him equates to mental torture," Arriba said.

"Even if Building 14 was the safest place [in Bilibid], if he was being locked up in solitary confinement, that equates to torture. He should have been transferred to a different facility," he added.