Chea Sim, a key Cambodian political figure after the fall of the Khmer Rouge government and an ally of Prime Minister Hun Sen, has died at age 82.

Sim was president of the ruling Cambodian People's Party since it was formed in 1991, president of the National Assembly of Cambodia from 1981 to 1998, and president of the Senate from 1999 until his death.

Senate secretary general Oum Sarith told Al Jazeera that Sim died in his home at 3:45pm on Monday.

"This is a loss for the country, the National Assembly, the Senate," he said, adding: "He helped get Cambodian out of the genocidal regime" of the Khmer Rouge, he said. "He had been sick for a long time."

Yim Leang, head of Sim's bodyguard unit, confirmed that the Senate president had died, but declined to comment further.

Sim became a revolutionary in the 1950s and like Hun Sen was a member of the communist Khmer Rouge when they seized power in 1975 after a civil war.

Both men fled the group to join a resistance faction groomed by neighbouring Vietnam, which installed them as Cambodia's new leaders after ousting the Khmer Rouge in 1979.

From April 6, 1992 to June 14, 1993, he served as the nation's interim leader before Cambodia became a constitutional monarchy. He also acted as head of state on behalf of King Norodom Sihanouk for brief periods in 1993, 1994, 1995 and 2004.

Sim was acting head of state again for a week after Sihanouk's abdication until Norodom Sihamoni became king on October 14, 2004.

Cambodian Prime Minister Hun Sen has already announced that he would assume the CPP presidency if Sim died.

Source: Al Jazeera And AP