Updated

Managua Mayor Alexis Arguello, a three-time world boxing champion, was found dead at his home Wednesday, his Sandinista Party's Radio Ya said.

Radio Ya said coroners were conducting an autopsy on the 57-year-old mayor to determine the cause of death, but it appeared to be a suicide. The La Prensa newspaper reported he was found with a gunshot wound to the chest.

The Hall of Fame boxer was the top fighter of the 20th century in his weight class, according to a panel of experts assembled by The Associated Press in 1999.

The death of Arguello prompted President Daniel Ortega to announced he was canceling a trip to Panama for the inauguration of President-elect Ricardo Martinelli.

Arguello fought against the Sandinista government in the 1980s after it seized his property and bank account, according to the International Boxing Hall of Fame.

But he joined the party to win the mayorship of the capital in 2008, though opponents alleged the vote was fraudulent.

"We are upset," said presidential spokeswoman, Rosario Murillo, who declined to give details about the death. "This is a heartbreaking announcement. He was the champion of the poor, an example of forgiveness and reconciliation."

Born in 1952, the Hall of Fame boxer fought 14 world champions and in 1981 he became the sixth man in boxing history to win a title in three weight divisions — featherweight, super featherweight and lightweight — according to the International Boxing Hall of Fame.

Arguello returned Sunday from Puerto Rico where he honored the late baseball Hall of Famer Roberto Clemente.