An opposition lawmaker condemned Thursday the sacking of Deputy Ombudsman Melchor Arthur Carandang for revealing information about an inquiry into alleged unexplained wealth of President Rodrigo Duterte and his family.

• Palace dismisses Deputy Ombudsman

In a statement, Sen. Antonio Trillanes IV said: "Not only is this illegal and unconstitutional since the Office of Ombudsman is an autonomous constitutional body, it is also highly unethical to fire the very same person investigating him."

"Up to now, Duterte cannot face this serious allegation about his hidden wealth amounting to billions of pesos of deposits; so, he is resorting to cover-up and harassment tactics," he added.

According to a 10-page decision issued by Executive Secretary Salvador Medialdea, Carandang is liable for graft and betrayal of public trust for publicizing evidence he had on the alleged undeclared wealth of Duterte and his family.

Carandang was sacked because of “guilty of manifest partiality” toward Trillanes, a staunch critic of Duterte, with the intent to broadcast information “adverse to the president”, according to Medialdea’s decision.

Trillanes first accused Duterte of keeping hidden wealth during the 2016 elections. He claimed that the President, then mayor of Davao City, had failed to declare P211 million in 17 accounts.

• Trillanes: Duterte a 'fraud,' didn't declare P211M in SALN

He also noted a VERA Files report that the Dutertes "failed to fully disclose in their Statements of Assets, Liabilities and Net Worth their joint deposits and investments, which exceeded Php100 million, under the Bank of the Philippine Islands (BPI)."

Trillanes, citing the report, said the transactions included "a P48.17 million placement in 2006 that grew to P55.13 million by 2013; a P40.55 million investment in 2009 that stood at P41.72 million in 2013; about $220,000, roughly P10 million, from 2006 to 2012; the purchase of P80 million in insurance policies in 2014; and a P16.85 million investment which begun in 2014."

The President has denied hiding his wealth from the public. He earlier said he is willing to be shot if his wealth turns out to be beyond P40 million.

“It could not be more than P40 million. It is a lifetime saving. Seventy-two [na] ako. I started to work when I was 27. Naging prosecutor ako. Pati kasali ang mga minana kong lupa. You can shoot me. You can overthrow me if you want kapag sumbobra ako doon,” he said in a speech last year.

“I promise you now in front of the soldiers and everybody: I will produce that account at sinasabi ko sa inyo, you can shoot me if it exceeds 40 million (pesos). Lifetime na iyan na savings ko. Hindi sosobra iyan, sigurado,” he added.

• Duterte: Shoot me if my wealth is beyond P40-M