Updated

A prominent human rights lawyer is demanding that Qatar compensate Dutch-based victims of an al-Qaida-linked Syrian extremist group, saying the Al Nusra group is financed by Qatar-based funding networks.

In a letter sent Monday to Qatar's ruling emir that was seen by The Associated Press, lawyer Liesbeth Zegveld accused the wealthy Gulf state of failing to take action against the group and said: "Qatar is therefore liable for the damages suffered by the victims."

Qatar denies funding extremist groups.

In her letter, Zegveld alleges that one of the victims was taken hostage by members of Al Nusra near Damascus in December 2012.

The man, whose identity was not released out of safety concerns, was repeatedly tortured, forced to watch the executions of two other hostages and subjected to a mock execution.