LONDON — A 40-year-old American man living in Scotland said Monday he’s sorry for posing as a Syrian lesbian blogger who offered vivid accounts of life amid revolt and repression in Damascus, a still-unraveling hoax that has exposed the difficulty of sifting truth from fiction online.

Tom MacMaster said he created the fictional persona of Amina Arraf and the “Gay Girl in Damascus” blog to draw attention to conditions in a Middle East convulsed by change.

“I never meant to hurt anyone,” the Edinburgh University graduate student wrote in a long apology on the blog. The university said it had suspended MacMaster’s computer privileges while it investigated whether he had breached its rules.

And as the deceit unspooled, a second blogger known as Paula Brooks, who posted some of the fraudulent Arraf’s comments on a lesbian news site, admitted to being a man who had adopted a fake lesbian persona.

The Washington Post reported late Monday that “Brooks” was a 58-year-old retired U.S. Air Force member named Bill Graber.

Graber admitted the deceit when phoned by the AP. He said he had set up the Lezgetreal.com site to advance the gay and lesbian cause and felt he would not be taken seriously as a straight man.

“LezGetReal was not meant to be deceitful or con anyone,” he said.

He also claimed to have helped unmask MacMaster by tracking his posts to computer servers in Edinburgh.

“He would have got away with it if I hadn’t been such a stand-up guy,” Graber said.

Gay-rights activists and bloggers say MacMaster’s deceit has endangered real people who are trying to tell their stories in authoritarian societies.

“He completely stole the limelight of real LGBT bloggers and activists in the Middle East and diverted it in a negative way,” said Dan Littauer of the website Gay Middle East.

Daniel Nassar, the pseudonym of a Syrian man affiliated with Gay Middle East, said MacMaster had put all gay Syrians in danger.

“If I was living in a country where I could sue this person because he has damaged me and damaged my cause … then I would,” he said.

MacMaster’s blogs about life as a Syrian-American lesbian grabbed international attention soon after they began in February. Alongside video clips and erotic poems, the writer wrote about a childhood in Virginia, daily life as a gay woman in Damascus, the growing protest movement and hopes for a future Syria freed from “dictators and rule by strong men.”

For readers hungry for news of the uprisings sweeping the Arab world, it was gold dust – a gripping, firsthand account of a country from which most foreign journalists are excluded.

A reporter for The Associated Press, who maintained a monthlong email correspondence with someone claiming to be Arraf, found the persona persuasive. The writer spoke about friends in Damascus, outlined worries about her father and hopes for the future of her country, and seemed very much like a woman in the midst of the violent change gripping Syria.