A United Nations human rights envoy says the Iranian government is responsible for egregious rights violations and remains a leading user of capital punishment.

Ahmed Shaheed, U.N. Special Rapporteur on Human Rights in Iran, told reporters, diplomats and rights activists in New York Monday that unfair trials, torture of prisoners, repression of journalists, persecution of religious and ethnic minorities, and other abuses continue unabated.

He also noted that Iran has executed more than 300 people in the first half of this year.

The U.N. envoy said there has been no visible improvement in recent years, even though Iran is a party to five legally binding international human rights treaties.

“I am concerned that I have not noticed any significant improvement in the human rights situation in Iran. If anything, things have become worse. Reports of torture continue. And they do so, also, as if to say that impunity is part of it. I find very rarely any investigation of allegations of torture, and where there have been done, they have not looked into the actual real perpetrators — the senior-most people who may be found culpable for these — have not been named or have no action taken against them.”

Shaheed said his latest report also details cruel treatment of human rights defenders. The report will be presented to a U.N. panel later this week.

He said suppression of alternative religions in the Islamic Republic is on the rise, and that members of the Baha'i community are the most persecuted religious minority.

Iran has dismissed the report as biased and politically motivated.

Shaheed has not been permitted to visit Iran to examine its human rights situation directly. He said the report is based on some 240 interviews with individuals who have reported violations of their rights.

The U.N. envoy said he would like to look into reports that sanctions against Iran's government over its nuclear program are hurting ordinary people.