The Scottish Police Authority has said there is no evidence a forensic officer from Dundee has been posting race-hate material online.
Several posts have been made by the man, who claims to have been a forensic officer in Dundee, on the infamous neo-Nazi Stormfront forum.
The forum, which has a worldwide network of users, was set up in the US in the 1990s to promote white supremacy.
In one post, made after anti-fascist campaigners demonstrated in Dundee, the man states he was abused while attending a break-in at the Al-Maktoum College in Dundee as a scene of crime officer.
There have been no break-ins at the college since it opened.
In another he claims to have inside information that three men convicted of murder after setting fire to a shop in Leicester as part of an insurance scam had been manufacturing drugs on the premises.
He also makes derogatory references to “chimps” and children of mixed heritage.
The Stormfront website contains thousands of sickening racist and anti-Semitic posts.
These include everything from queries about whether history books have unfairly maligned Adolf Hitler to complaints about television programme The One Show.
Anti-fascist campaigners demonstrated in Dundee on December 8 after a far-right group calling itself the Scottish Nationalist Society put up white supremacist stickers around Dundee.
Three days before the demonstration the man, who uses the name DrFredMBongo and claims to have a masters in DNA analysis, wrote: “Went and had a look at Stand up to Racism Tayside to see where about the protest is going to be in Dundee.
“Of course, instead of the main street, which has plenty of room, pedestrianised and a lot of foot traffic to show off to, they’ve decided to do it beside the big shopping centre- close to the posh coffee shops, and means blocking the main bus route and two other main roads, meaning more hassle for the people and the police.
“Also, the other regional groups are coming up as rentamobs, so more trouble. All this for a few stickers.”
He then claims he was abused when working as a SOCO – scene of crime officer – when called to the Al Maktoum College of Higher Education after a supposed break-in.
In a post about the Leicester explosion, the person wrote: “Hearing from former forensic colleagues that it was drug manufacturing gone wrong, and hit the gas line.”
Scene of crime officers are employed by the Scottish Police Authority, rather than Police Scotland.
An SPA forensic services spokeswoman said: “We expect all our employees to maintain a high level of professional and personal integrity.
“All our staff are required to abide by the SPA Code of Conduct and the SPA Forensic Services Code of Practice. Any member of staff found to be breaching these codes would be subject to disciplinary proceedings.”
Dr Abi Abubaker, acting head of Al-Maktoum College, said: “We are saddened that we find ourselves in a position of responding to a comment that is totally unfounded and completely untrue.
“Firstly, since the college opened its doors, we are pleased to say we have not had to report a single break-in, and the police will confirm that.
“In general terms, we enjoy strong, open and mutually beneficial relations with the police at all levels, and again I am sure the police will readily agree with me on this.
“The college exists to build bridges between communities and I believe our reputation in Dundee confirms this.”
Far-right fanatics have targeted Dundee in the past two years.
In 2017 an offshoot of the banned group National Action, called System Resistance Network, targeted a charity helping gay, lesbian, bisexual and transgender teens in Dundee.
Last year the Scottish Nationalist Society put stickers up around Dundee and posted photographs of their members posing at Dundee city centre landmarks.