BEIRUT (Reuters) - Iran's Supreme Court has upheld a death sentence against an Iranian academic with Swedish residency convicted of espionage, Amnesty International and his family said on Tuesday.

Ahmadreza Djalali, a doctor and lecturer at the Karolinska Institute, a Stockholm medical university, was accused of providing information to Israel to help it assassinate several senior nuclear scientists.

Djalali was arrested in Iran in April 2016 and later convicted of espionage. He denied the charges, Amnesty said.

At least four scientists were killed between 2010 and 2012 in what Tehran said was a program of assassinations meant to sabotage its efforts to develop nuclear energy. Western powers and Israel said Iran aimed to build a nuclear bomb. Tehran denied this.

The Islamic Republic hanged a man in 2012 over the killings, saying he had links to Israel.

Djalali's lawyers were told on Saturday that the Supreme Court had considered his case and upheld his Oct. 24 sentence in a secret process without allowing them to file defense submissions, London-based Amnesty said.

"This is not only a shocking assault on the right to a fair trial but is also in utter disregard for Ahmadreza Djalali’s right to life," Magdalena Mughrabi, Amnesty's deputy director for the Middle East and North Africa, said in a statement.

Vida Mehrannia, Djalali's wife, said the whole family were in shock at the decision and that they had informed the Swedish government about the latest development in the case.

"The judicial process was not fair and legal from the beginning. None of the court sessions was held in public and the interrogators imposed their decision on the judges," she told Reuters by telephone from Stockholm.

The Iranian judiciary could not be reached for comment.

Amnesty said in October that the court verdict against Djalali stated he had worked with the Israeli government which then helped him obtain a Swedish residency permit.

Djalali was on a business trip to Iran when he was arrested and sent to Evin prison. He was held in solitary confinement for three months of his detention and tortured, Amnesty said.

It said Djalali wrote a letter inside Evin last August stating he was being held for refusing to spy for Iran.

Sweden condemned the sentence in October and said it had raised the matter with Iranian envoys in Stockholm and Tehran.

Seventy-five Nobel prize laureates petitioned Iranian authorities last month to release Djalali so he could "continue his scholarly work for the benefit of mankind".

They said Djalali has suggested it was his refusal to work for Iranian intelligence services that led to this "unfair, flawed trial".

The United Nations and international human rights organizations regularly list Iran as a country with one of the world's highest execution rates. Rights groups have criticized Iran for its regular resort to capital punishment.

(Reporting by Babak Dehghanpisheh and Bozorgmehr Sharafedin; editing by Mark Heinrich)