Former Panamanian dictator Manuel Noriega is in a critical condition in hospital after undergoing two brain surgeries, according to his family and lawyer.

The 83-year-old underwent the first procedure on Tuesday morning to remove a benign tumour from his brain. But after that surgery, doctors discovered a haemorrhage that forced them to go back in that afternoon.

He was listed in critical condition in the intensive care unit of Santo Tomas public hospital in Panama City, attorney Ezra Angel said on Tuesday night.

Angel said doctors had succeeded in stopping the bleeding during the second procedure and Noriega was returned to intensive care.

"He is sedated," the lawyer said. "His condition is critical after undergoing a [second] open brain surgery in less than eight hours."

A close ally of Washington for decades and a paid informant of the CIA, Noriega ruled Panama from 1983 to 1989 before the US invaded in 1989, toppling his regime and ending a drug-trafficking career that associated him with Colombian kingpin Pablo Escobar.

He was then jailed in the US for 20 years for drug-trafficking, before serving time in France for money laundering.

In 2011 he was extradited back to Panama after being convicted in absentia of crimes committed during his rule and is still serving that sentence. 

Judicial authorities had granted Noriega a period of house arrest until April 28 to undergo the operation.

Although never officially Panama's president, Noriega, then a general, became the de facto head of government in 1983, two years after dictator General Omar Torrijos was killed in a plane crash Noriega was later accused of masterminding.

Noriega orchestrated the disappearance of scores of opponents, some of whose bodies later turned up in exhumations at the former Tocumen military base, bound and showing signs of torture.

"I hope that one day the country will know the truth about General Noriega, and the families who lost their loved ones can be free, close this chapter and move on," Panama's current President, Juan Carlos Varela, said on Tuesday.

Source: News agencies