More than 40 people have been arrested on the basis of tip-offs after police circulated photographs of demonstrators at a December rally which turned deadly, a police website reported on Tuesday.

But the reformist ex-president Mohammad Khatami defended the protesters and condemned the new wave of arrests of government critics launched after the bloody protests during the Shiite mourning rituals of Ashura on December 27.

Despite the roundup, Khatami, a key figure in the opposition camp which has infuriated hardliners with its street protests, defended the protesters.

Khatami, who was meeting with a group of released post-vote detainees, slammed those in power who “commit violence with complete immunity” against demonstrators.

Khatami also accused Iran’s leadership of lying to the people.

“Many lies have been told these days and many promises have been made but people see those in charge of their affairs have not done much,” the former president said.

“So people realise that many of the protesters are not ill-intentioned and their protest is reasonable,” he said in comments carried by his Baran Organisation’s website.