AFP - Iran's parliament will investigate claims by a labour protest leader that he was tortured in prison following strikes at a sugar factory, the semi-official ISNA news agency reported on Sunday.

Alireza Rahimi, a member of parliament's presiding board, said his request for an investigation had been accepted by speaker Ali Larijani, according to ISNA.

It followed claims by Esmail Bakhshi, written on his Instagram account and reported by the reformist Etemad newspaper, that he was tortured during 25 days in detention in southwestern Khuzestan province late last year.

Bakhshi was one of the organisers of weeks-long protests at the Haft Tapeh sugar factory in Shush over unpaid wages and alleged criminal activity by new private owners.

Ali Motahari, an outspoken member of parliament, wrote a column in Etemad on Sunday titled "Source of shame", demanding answers from the intelligence ministry.

The governor of Khuzestan, Gholamreza Shariati, denied Bakhshi's claims.

"I checked with the relevant bodies and the claim of torture was strongly denied," he told the Jamaran news site.

Rahimi said Intelligence Minister Mahmoud Alavi will attend the commission hearings in parliament, according to ISNA.

The strike at Haft Tapeh, which has around 4,000 workers, largely ended in December after the workers received their wages.

Iran has been hit by strikes over working conditions in several key sectors this year, including education, mines, transport and the steel industry, mainly outside Tehran.

In November the head of Iran's judiciary warned restive workers against creating "disorder".

"Workers should not allow their demands to become an excuse and an instrument for the enemy," Ayatollah Sadegh Larijani said, quoted by the judiciary's news agency Mizan Online.