Football pools giant Littlewoods Leisure is being sued by a firefighter for £30m over allegations that the firm stole a patented version of Spot the Ball.

William Constantine, from County Durham, has lodged a writ with the company claiming damages and compensation for a version of the popular gambling game which he claims he invented.

It is understood that six years ago, Mr Constantine approached Littlewoods with the idea of using transfers instead of pen marks to indicate the mystery position of a football on a picture.

The claim is that this proposal was rejected and that Littlewoods later launched a similar version, which Mr Constantine believes has infringed a patent he lodged with the Patents Office around the time of his original approach to the firm.

Littlewoods Leisure, which was sold to the Scottish services group Sportech for £161m last year, told the Independent on Sunday yesterday that it was "strenuously defending" the lawsuit.

Robert Haggis, company secretary, told the newspaper: "We get quite a few members of the public coming to us with ideas - it's the nature of the business.

"We looked at Mr Constantine's idea but we did not run with it at the time. Having a sticker with lots of crosses is not a novel idea.

"He has managed to get hold of a patent, much to our chagrin.

"The basis of our defence is that the patent should not have been issued. We have inherited this but if we lost the matter we would have to re-examine our agreement with Littlewoods and possibly pass it on back down the chain."

Mr Constantine was last night out of the country.

His spokesman said details of the legal action had been released without his consent or knowledge