File photo of former Panamanian dictator Manuel Noriega
Former Panamanian dictator Manuel Noriega is seen during his arrest by U.S. Drug Enforcement Agency operatives in this 1990 file photo. REUTERS

Manuel Noriega, Panama's ruthless drug-running military dictator of the 1980s, is to be returned home on Sunday, headed for a jungle prison to serve a 20-year term for the murders of opponents during his rule.

Noriega, now 77, was toppled in a U.S. invasion of Panama in 1989 and has spent the last two decades behind bars, first in Florida and then in France after being convicted for drug trafficking and money laundering during his time in power.

Panama's attorney general and a doctor will be part of the team accompanying Noriega on a commercial flight back to his homeland, expected to leave Paris on Sunday morning.

A physically diminished shadow of the strongman once known for waving a machete while delivering fiery speeches, Noriega's return is unlikely to have a major political impact on a country that has enjoyed an economic boom in recent years.

Widely reviled when he was Panama's de facto leader from 1983 until 1989, his small cadre of remaining supporters has kept a low profile and even bitter opponents dismiss Noriega as part of a distant, shadowy past.

Much of the focus on Noriega will be on whether he sheds any light on the dictatorship's mysteries, including some 100 unsolved killings or disappearances in the period of army rule from 1968 to 1989.

Noriega was convicted in absentia in three homicide cases involving 11 murders, including the 1985 beheading of Hugo Spadafora, a physician who threatened to reveal Noriega's drug ties, and the 1989 execution-style slaying of nine officers who staged a failed coup. Some reports say more than 11 soldiers were killed in the massacre.

Noriega was sentenced to 20 years in each case, and will serve the terms concurrently. A special unit has been prepared for him at a penitentiary near the Panama Canal surrounded by tropical rainforest.

New Charges

He will also face charges over the murder in 1970 of Heliodoro Portugal, an opponent of Panama's military leaders.

We hope he talks and says where the rest of the disappeared are, what happened to those who were killed, said Patria Portugal, who has spent decades fighting for justice in her father's case. We hope ... he asks for forgiveness of the Panamanian nation for the all the crimes he committed.

Although Noriega controversially qualifies for house arrest due to his age, the decision rests with the government. His lawyer, Julio Berrios, said house arrest would also imply an acceptance of his sentence and mean Noriega could not launch any legal challenge against the convictions.

Leaders of a civilian movement that protested Noriega's regime in the late 1980s have rallied ahead of his return to urge the government to keep him in prison.

Noriega rose to the top of the armed forces by tenaciously gathering intelligence on friends and foes alike and became de facto leader in 1983.

Originally a Central Intelligence Agency protege, Noriega fell out with Washington over his ties to Colombian drug traffickers and his rigging of elections.

The U.S. invasion in December 1989 came soon after a botched coup that the United States could have used to nab Noriega, who was briefly held by rebel officers.

Tensions were further stoked prior to the invasion when Noriega forces shot and killed a U.S. Marine at a military checkpoint in Panama City. U.S. forces were posted in the country at the time to protect the Panama Canal, which was handed over to Panamanian control at the end of 1999.

(Reporting by Sean Mattson; Editing by Kieran Murray)