Bahrain accused a prominent activist on Monday of publishing fabricated images on the Internet and summoned him for questioning in an ongoing crackdown following pro-democracy protests the state put down by force. The official Bahrain News Agency (BNA) said Nabeel Rajab, head of the Bahrain Center for Human Rights, had published doctored images with links to social media site Twitter of one of two men who died at a detention center on Saturday.

The deputy adviser for legal affairs at the interior ministry announced that Nabeel Rajab published false images on social media site Twitter of Ahmed Isa Sager, BNA said.

The opposition has said it suspects Sager died from the effects of torture in detention. Bahrain's government denies any torture but says all such accusations will be investigated.

The adviser said that the images published were different to those taken of the deceased with the knowledge of the coroner after death, BNA said, adding Rajab's case would be transferred to military prosecutors. It did not say how the pictures were different or the significance of the differences.

Rajab, who has not been questioned yet, said on Twitter he had not fabricated any images.

All this effort to strike at my credibility because the number of followers I have on Twitter and Facebook is more than the viewers of Bahrain TV, he wrote early on Sunday.

Bahrain saw the worst sectarian clashes since the 1990s last month after mostly Shi'ite protesters, emboldened by uprisings in Tunisia and Egypt, took to the streets urging democratic reform, though some radicals called for the overthrow of the monarchy.

Weeks of protests prompted the Sunni-led government to impose martial law and invite in troops from Sunni-ruled neighbors such as Saudi Arabia and the United Arab Emirates.

Since then the U.S.-allied Bahrain government has launched a crackdown against opposition activists, journalists and Shi'ite villagers and accused Iran of fomenting the unrest.

U.S.-allied Gulf Arab states are worried about the influence of non-Arab Shi'ite power Iran in the Gulf region.

Majority Shi'ites in Bahrain say that questioning of their allegiance to Bahrain is evidence of what they call their second class status in the island state. The government denies this.

(Writing by Andrew Hammond; Editing by Nick Macfie)