And the medal for worst Olympic participant goes to...

Lord Coe urged the public to secure items from the Games (EPA)

Lord Coe's invitation to "own a piece of Olympic history" has turned sour after fans threatened to sue the company behind the auction of memorabilia from last year's Games, accusing it of failing to deliver the goods.

Olympic addicts were invited to snap up items ranging from the peasant outfits worn in the Opening Ceremony to the batons carried in relay finals and signed outfits worn by Bradley Wiggins and other British medal-winners.

But Innovative Sports Ltd, the Canadian company running the memorabilia.london2012.com auction site, has admitted that it does not possess some of the exclusive items it sold to customers, who have complained that they have yet to receive their goods, months after purchasing.

Damian Kelly, a solicitor from Leeds, told The Independent: "I bought all the result sheets for Michael Phelps' historic swimming events in August. They still haven't arrived. I have spent £7,000 on outstanding items. To say I am annoyed is an understatement."

Mr Kelly said he had contacted Innovative Sports in Vancouver. "I was told they could get Seb Coe to sign an Olympics book instead. With all due respect to Seb, it's no substitute."

Mr Kelly claims he was told that Innovative Sports did not yet have the Phelps results sheets it had sold. "Advertising items for sale you do not possess could be a case of fraud," said the solicitor, who has approached other customers who are also missing items. "I am speaking to a barrister soon about launching legal proceedings," Mr Kelly said. The company has strongly denied any allegations of fraud.

Another customer, Ferris Cowper, wrote on a blog: "I was stupid enough to buy an Olympic Torch at a cost of £4,300, thinking I was buying from London 2012. This outfit took my money and failed to deliver the torch after four different delivery date promises."

Mr Cowper has taken legal advice to discover if "a crime may have been committed by organisations involved with this activity by taking money for goods where there is no intention to supply."

Customers complained that emails to Innovative Sports were no longer being answered. Another was told that the delay on his Bradley Wiggins item was "due to his accident", after the cyclist was hospitalised following a road collision last November. "Not sure how you can sell an item that you don't actually have," the customer wrote.

Concerns were first raised over Innovative Sports, which claims to be "one of the premier sports marketing companies in the world", after the limited company behind the sale notified Companies House that it was dissolving and was removed from the register of companies, two days after the Games ended. The company had said this was a mistake and the company was later re-instated.

Jon Curleigh, a director at Innovative Sports, said: "We were overwhelmed by the success of the Games and caught off guard by the demand. Unfortunately some of the products didn't materialise in the way they should have. The issue is people wanting products that we just don't have. We are offering everyone affected a 100 per cent full refund. Some people don't want the refund, they want their products. I don't know what to do about that."

Mr Curleigh denied any suggestion of fraud because "there was no absolutely no intention to deceive". Delays had been caused by the need to authenticate products. In other cases, athletes like Wiggins had been unable to sign items because they were injured, Mr Curleigh suggested.

A message on the official auction website states that Innovative Sports will start dispatching items on 21 January following the relocation of its warehouse and thanked customers for their "patience and understanding".

A Locog spokesman said: "We are not aware of any issues regarding the memorabilia website but will contact the company concerned and ask about these claims and will look into any specific information provided to us."

'We paid our money but they claim there's no record of it'

Charlotte Roberts, from Oxford, bought a pair of lamp-post banners depicting the Olympic and Paralympic logos for £105 as a Christmas present for her daughter, Alexia.

She said: "We ordered our items on 2 December, well before the Christmas deadline and they still haven't arrived. Our nine-year-old is Olympics-mad and she was very upset."

Mrs Roberts complained to Locog, which is giving disappointed customers the email address of Innovative Sports in Canada. "We heard nothing so we called the company in Vancouver," Mrs Roberts said. "They said they didn't have a record of what had been dispatched." Mrs Roberts added: "We don't know if our banners will ever be delivered."