David Castro, the 68 year-old former chief of the Presidential Commission on Good Government, was given back his passport after he checked into a New York hospital for heart surgery, PCGG chief Jorge Sarmiento said.
Castro and Edilberto Marcos, a Filipino who claimed to be the son of the late dictator Ferdinand Marcos, were arrested in the United States five weeks ago.
They were reportedly trying to sell an undercover Federal Bureau of Investigation (FBI) agent a fake 20-million-US-dollar share certificate in gold worth 800 million dollars supposedly stored in a Swiss bank.
Castro reportedly told FBI agents he was acting as a government representative trying to collect taxes on the transaction involving the gold.
But President Gloria Arroyos government disowned him.
With the FBIs act of returning his passport, Castro "is free to do whatever he wants," Sarmiento told reporters.
He said Castro had been released on humanitarian grounds.
The PCGG released a report from the Filipino embassy in Washington that said Castros lawyers demanded the FBI pay for his hospital costs in exchange for his decision to cooperate with them on the prosecution of Edilberto Marcos.
"However, initial reports reaching our office said that the FBI no longer may be in need of Mr Castro since they already have a strong case against Mr (Edilberto) Marcos," the report said.
Sarmiento said Castros doctors at the hospital had recommended he undergo angioplasty, surgery to clear arteries.
The late president Marcos has only one acknowledged son, Ferdinand Junior, who is now governor of the northern Philippine province of Ilocos Norte.
President Marcos was deposed in a popular revolt in 1986 and died in exile in 1989.
The PCGG has been searching for years to recover the billions of dollars that Marcos allegedly stole during his 20-year rule. Shiela Crisostomo