Were you overcharged for this replica shirt back in 2001?

Clyde & Co has placed an advert asking fans to get in contact if they bought England or Manchester United shirts in 2000 or 2001.

Several sportswear retailers were fined by the Office of Fair Trading (OFT) in 2003 for illegally fixing the price of these shirts.

Clyde & Co says a new law means consumers can now sue the price fixers.

The law firm is acting on behalf of the consumers' association Which? because the organisation is attempting to launch a representative action on behalf of people who bought the shirts.

No win, no fee

The advert has been placed in the football magazine When Saturday Comes, urging affected fans to sign up with the law firm on a "no win, no fee" basis.

If a company has been found guilty of price fixing, the powers we have are, potentially, to claim some money back Which?

It says it is interested in hearing from customers even if they no longer have proof of purchase such as a receipt.

The OFT spent two years investigating complaints from retailers that manufacturers had refused to supply them with the shirts because they planned to sell them at a discount.

Ten companies - including Manchester United and the Football Association - were eventually fined more than �16m for colluding amongst themselves to keep the price of the replica shirts artificially high.

The sportswear retailer JJB Sports was fined �6.3m, shirt manufacturer Umbro �5.3m and Manchester United �1.5m.

New law

Which? is planning to use powers granted to it under the Enterprise Act for the first time.

This gave it the power to go to the Competition Appeals Tribunal to claim compensation for a group of consumers.

A spokeswoman said: "If a company has been found guilty of price fixing, the powers we have are, potentially, to claim some money back."

However, it is not an open and shut case.

Which? said it did not know how many people would respond to its advert and admitted it might have difficulty establishing that any of the individuals had clearly lost money.

As a result it might not, in fact, end up launching a formal claim.

"It's not always easy to establish individual loss," admitted the spokeswoman.