MANILA - (UPDATED) Former Senate President Ernesto Maceda is in critical condition after undergoing a gallbladder operation, his family told ABS-CBN News.

Maceda's daughter-in-law Rica Vergara-Maceda said the veteran lawmaker had the operation last Saturday. Although he was fully conscious after surgery, Maceda slipped into a coma on Sunday, but was revived afterwards.

On Monday morning, Maceda lost oxygen.

In an interview on ANC Monday afternoon, Maceda's son, Atty. Ernesto Maceda Jr., said his father remains on life support.

"We'd like to make a clarification that it's not true (that he passed away). He's now, as you said, in critical condition. He's now on life support, but he's still very much with us," the younger Maceda said.

"We're waiting for the arrival of my brother from abroad, at which time we will make an announcement. Hopefully, that announcement would take place longer, rather than sooner than we would like," he added, saying they would also consult with doctors on the next step to take.

Senate earlier set the Philippine flag at half-mast after learning of Maceda's misreported death. But by 2:40 PM, Senate authorities raised the flag again.

Maceda served for 3 Senate terms - one during the pre-martial law Congress, two during the post-EDSA legislature. He is best known for his privilege speeches exposing government anomalies and other controversial issues, earning him the moniker "Mr. Expose."

Among his high profile exposes was the PEA-Amari scam involving the overpriced purchase of reclaimed land in Manila bay, which he called "the grandmother of all scams."

Maceda also triggered a Senate probe on the so-called 'Brunei Beauties" - female celebrities who were allegedly into high-class prostitution in the oil-rich state.

Before he ran for senator in the 1987 elections, Maceda was Cory Aquino's Secretary of Environment and Natural Resources.

During his long and storied government career, Maceda also occupied five Cabinet positions. He was Presidential Assistant on Community Development, Chairman of the Commission on Reorganization, Secretary of Commerce and Industry, and Executive Secretary during the Marcos administration; Secretary of Environment and Natural Resources during Cory Aquino's term, and Philippine ambassador to the United States during the administration of Joseph Estrada.

- With reports from Zandro Ochona