Dozens of rights activists, prominent lawyers and former prosecutors have written to the UN Human Rights chief urging him to try to prevent the execution of an Iranian boxer.

Mohammad Javad Vafa'i Sani who was imprisoned for his role in anti-government protests in 2019 was informed on Wednesday that his execution verdict had been finalized, according to the letter sent to the UN official dated July 19.

"We ask that you make an urgent public call for the Iranian authorities to halt Vafa'i Sani's imminent execution sentence," said the document, signed by 83 people including the former head of the International Criminal Court Judge Sang-Hyun Song, more than a dozen current and former UN human rights officials as well as former prosecutors.

Iran's judiciary was not immediately available to comment on the matter. However, his lawyer Babak Paknia said in a tweet that the judiciary had not notified them about the verdict.

A spokesperson for the UN High Commissioner for Human Rights Volker Turk said: "We have received information on this case and are following up on it and gathering additional information."

Iran was rocked by major protests last year sparked by the death of 22-year-old Mahsa Amini in September 2022 while in the custody of the country's morality police.

Since then, at least seven people have been executed for verdicts linked to the unrest, which the clerical rulers have accused the country's foes of fomenting.

Turk has been pushing for a trip to the country and a meeting with Iran's Supreme Leader Ayatollah Ali Khamenei, although there has been little if any indication those efforts are bearing fruit.