At least half a dozen auction houses across the country are believed to have offered such works, with most making sums in the region of £1500-4000.
ATG understand that examples have also been offered privately.
James Kelly, director of The Hirst Authentication Committee (HIAC), the organisation authorised by Hirst to authenticate his works, told ATG that these works "appear to have been made by one person or group of people".
"Following our most recent authentication session, we became aware of certain counterfeit works circulating on the secondary market," he said.
"Where possible, we have contacted the sellers of these pieces to inform them of our concerns over the authenticity of the paintings.
"We are currently in the process of contacting all UK auction houses and galleries dealing in Damien Hirst's secondary market works, to remind them that we are here to offer help and encourage them to accurately verify the provenance of the works they are selling."
Spin Paintings
HIAC did not want to release any details which may furnish potential copycats with the information to help them make accurate fakes. However, one London-based art dealer who bought three non-authentic 'Damien Hirst' acrylics at auction said the fakes tended to come in cheap frames and had no viable provenance to galleries such as White Cube which originally sold Hirst paintings.
The dealer in question bought the three 'spin' paintings from Mallams Oxford last July. All had a signature on the verso alongside a stamp stating they were made in Damien Hirst's Gloucester studio.
They were catalogued as works by 'Damien Hirst (b.1965)' and offered with estimates of £2000-3000 each.
After paying a total of £11,776 (including premium), the dealer submitted them to HIAC.
With the committee holding authentication sessions approximately six times a year, the dealer did not hear until October that the works and signatures had been declared "categorically" as fakes. As a result of their findings, HIAC stamped the works 'Not a Hirst' to prevent them ever being resold as a Hirst artwork.
After making unsuccessful attempts to obtain a refund, the dealer is in dispute with Mallams. He believes no proper checks were carried out in advance of the auction.
Mallams' terms and conditions state that deliberate forgeries may be returned within 21 days, but the dealer told ATG that it was impossible for the authentication body to make a ruling on a work within that time frame.
Ben Lloyd, director of Mallams, told ATG: "When we became aware of this matter we reported it to the police.
"It's now in the hands of our insurers and their lawyers who are in contact with both the buyer and the vendor."
He added: "We are making every effort to resolve the matter."
Kelly said that HIAC would "urge anyone either selling, or looking to buy, a Damien Hirst spin painting on paper or canvas to contact HIAC for advice". He added: "It is ultimately the seller's responsibility to verify the provenance of an artwork or they should submit the work to us for authentication."
