An Iranian man has died in jail after his death sentence for taking part in anti-government protests was overturned by Iran's Supreme Court.

Javad Rouhi was arrested last year during protests triggered by the death in custody of Mahsa Amini, who was held for allegedly wearing "improper" hijab.

Officials say Mr Rouhi, 35, died from ineffective hospital treatment after suffering a seizure in prison.

Activists are holding the authorities responsible for his death.

"Unfortunately, [Mr Rouhi] died despite the actions of medical staff, and a legal case has been filed to follow up on the reason for his death," the Iranian judiciary's news website, Mizan, reported.

However, an hour before the official announcement on Thursday, several human rights activists announced the death of Mr Rouhi on social networks and accused judicial and security authorities of "killing" him.

Mr Rouhi was arrested just days after 22-year-old Mahsa Amini died in the custody of Iran's infamous morality police, triggering months of national unrest.

He was found guilty of leading rioters, destroying property, and apostasy for allegedly burning a Quran during a demonstration.

However, activists are currently sharing video clips from last year showing him dancing during the protests.

Amnesty International says he was subjected to floggings, freezing temperatures, electric shocks and had a gun held to his head to force him into confessing.

Mr Rouhi was originally handed a triple death sentence on charges of blasphemy, destroying public property and inciting people against national security by a court in Nowshahr, a city in northern Iran.

However, the sentence was overturned by the country's supreme court in May, referring his case to another court for re-evaluation.

The court's review of the case files revealed that Mr Rouhi had participated in the protests individually, and his actions did not align with the legal definitions of "moharebeh" (waging war against God) and "corruption on earth", offences that can result in the death penalty under Islamic jurisprudence. (Courtesy, excluding headline, BBC)