The buyer of a letter purportedly written by Captain Thomas Hardy from HMS Victory six days after the Battle of Trafalgar has belatedly received a full refund after it proved to be a facsimile of a letter in a public collection.

The facsimile letter purportedly written by Captain Thomas Hardy from HMS Victory six days after Trafalgar.

On November 6, 2004, London rare book dealers Maggs Bros successfully bid £13,800 (£15,525 including buyer's premium) for the apparently important letter offered by Buckinghamshire auctioneers Dickins of Middle Clayton.

Framed under glass and written on a single folio of wove paper, 11 x 145/8in (28 x 37cm), and dated October 27, 1805, it was addressed to Hardy's brother-in-law, Dorchester lawyer John Manfield. Its opening lines read: "We have on the 21st obtained a most Glorious Victory over the Combined Fleets but it has cost the country a life that no money can replace and for whose Death I shall forever mourn…" The letter had first came to light 99 years ago when it featured in a Nelson and Trafalgar exhibition in Dorchester and, rather more recently, attracted wide interest when it was featured on an episode of BBC's Antiques Roadshow.

Clouding the legal issues of caveat emptor (buyer beware) that still govern the auction process, doubts regarding the authenticity of lot 573 had been expressed to auctioneer John Dickins prior to the sale.

An expert in postal history had, among other points, questioned both the immaculate strike of the postmark and the presence of a heavy vertical crease that was inconsistent with the survival of an unbroken wax seal.

However, others who viewed the letter had been convinced of its integrity and no presale announcement regarding these doubts was made.

Magg Bros' representatives had been happy when viewing the letter under glass prior to the sale and had subsequently bought it over the telephone well above the £5000-8000 estimate.

However, doubts appeared after purchase when the document was removed from its frame and it quickly emerged that the letter was a facsimile created from the book Nelson's Hardy by Broadley and Barethelot.

The original letter is on view at the Dorset County Record Office.

Negotiations between Maggs and Mr Dickins lasted for several months before a settlement was reached. Both parties say they incurred substantial legal fees.