An Iranian court has sentenced four people to death after they were said to be involved in the country’s biggest fraud case, amid rumors of corruption within the government, Financial Times reports.

Four out of the 39 suspects accused of being involved in the bank fraud, which was worth $2.8 billion, were convicted to death, while the others were sentenced to life imprisonment and face jail terms as long as 25 years, according to Iran’s judiciary spokesman Gholam-Hossein Mohseni-Ejei.

One of the accused is allegedly linked to the president’s allies. Billionaire and so-called mastermind Mah-Afarid Khosravi is linked to the president’s chief of staff, Esfandiar-Rahim Mashaei, Iranian media reported. Mr. Khosravi was charged with embezzlement, forgery, money laundering and “disruption of the economic system”.

The case comes as a blow for Iran’s president, Mahmoud Ahmadinejad, who has been criticized by conservative opposition, underlining the tensions between the president and supreme leader, Ayatollah Ali Khamenei.