An Iranian forest ranger whose death sentence for murder had been suspended was gunned down on Saturday by a relative of the man he allegedly killed, official sources said.

Boroumand Najafi was sentenced to death earlier this year after killing a man he thought was a poacher in 2020 in western Iran's Kermanshah region.

In April, the judiciary suspended his death sentence and ordered a re-trial after an appeal by the defence.

"Today Boroumand Najafi was killed outside the court by three Kalashnikov bullets fired by the victim's father" following a hearing, Kermanshah prosecutor Shahram Karami said on state television on Saturday.

"Shortly before that, a relative of the victim attacked a prison guard accompanying Najafi with an axe, wounding him in the hand."

"The attacker and his accomplice fled," Karami added.

Iranian media reports have said dozens of forest rangers have been killed by poachers in recent years across the country.

In May, one person was executed after being sentenced to death for killing two forest rangers in Iran's northwest in April last year.