TEHRAN — Iran’s judiciary on Saturday executed a billionaire businessman who had been convicted of playing a central role in a $2.6 billion corruption case that has roiled the country’s banking system and political leaders.

State television reported that the businessman, Mahafarid Amir Khosravi, was hanged early Saturday in Evin Prison in Tehran. He was convicted of forging letters of credit with the help of high-level bank managers in order to get loans from one of the country’s largest banks, Saderat.

Political opponents of former President Mahmoud Ahmadinejad have often accused him and his team of advisers of having been connected to Mr. Amir Khosravi, who is said to have earned his fortune in banking and railroads.

The embezzlement case, the largest case of fraud since the 1979 revolution, came to light almost immediately after a public falling out between Iran’s supreme leader, Ayatollah Ali Khamenei, and Mr. Ahmadinejad in 2011 over control of the Intelligence Ministry, which was said to have been investigating the case.