"The court has established premeditated murder and passed the execution sentence," Judiciary spokesman Gholamhossein Esmaili said on July 30, according to Mizan, a news agency affiliated with the Iranian Judiciary.

Najafi, 67, also received a two-year jail sentence for possessing an illegal firearm but was acquitted of battery charges, the spokesman said.

Najafi’s wife, Mitra Ostad, was found dead at their home in northwestern Tehran on May 28.

Officials said that Najafi had surrendered to authorities and confessed to killing his wife over family issues.

His lawyer, Hamid Goudarzi, said he would appeal the court ruling.

"We hope the Supreme Court accepts our concerns and helps justice to be served by rejecting the verdict," the semiofficial ISNA news agency quoted Goudarzi as saying.

The high-profile case received extensive media coverage in Iran, where gun violence is rare, especially among the political and economic elite.

Polygamy is legal under Islamic laws enforced in the country.

Najafi resigned as mayor last year after coming under criticism by hard-liners for attending a ceremony at which young girls were dancing. He cited health reasons for his resignation.

Najafi has also served as one of the country's vice presidents.

With reporting by AP and AFP