The former leader of Panama, General Manuel Antonio Noriega, is in intensive care after suffering a haemorrhage following brain surgery.
His daughter Thays said he was critically ill and had been taken back to the operating theatre at the Santo Tomas hospital in Panama City.
Mr Noriega was released from prison in January to allow him to prepare for the operation.
He was jailed in Panama for murder, corruption and embezzlement.
Although he was never the actual president of Panama, General Noriega was the key figure from 1983 to 1989 – and a key US ally in Central America for four decades.
The former military ruler, who is now 83, was jailed following the US invasion of Panama in 1989.
After serving 20 years in the US he was sent to France, where he was sentenced to seven years for money laundering.
Mr Noriega was convicted in absentia of crimes carried out during his rule and extradited from France to Panama to serve his sentence in 2011.