Someone claiming to be her cousin wrote on the website that Arraf had been arrested, prompting supporters to set up a "Free Amina Abdallah" group on Facebook that attracted nearly 15,000 followers.

But reports Radio Netherland her supposed arrest lit scepticism about reality and MacMaster came clean in a message admitting to sole author of the posts.

"I never expected this level of attention," he wrote in an "Apology to readers" datelined Istanbul, Turkey, where he and his wife were on holiday. "While the narrative voice may have been fictional, the facts on this blog are true and not misleading as to the situation on the ground."

But he said he was worried that his actions could boost the Syrian regime's claims that other Internet activists reporting on the crackdown were also fake.

MacMaster said he was "somebody who has aspirations as a novelist" and he expressed regret to The Guardian, wanting to shut the blog and "phase out the character" but "having her abducted was not the way to do it."

Edinburgh University is to "suspend his computing privileges" pending results of an investigation into his behaviour and "will investigate whether the student has breached University computing regulations," said a statement.

The Guardian said recently that evidence pointed towards MacMaster and his wife Britta Froelicher, studying for a doctorate in Syrian economic development at Saint Andrews University.