The discovery of bird flu at a Bernard Matthews farm yesterday is a devastating setback for the man who proudly proclaims himself "Europe's biggest turkey manufacturer".

Mr Matthews's spokesman was quick to reassure consumers that none of the infected birds had entered the food chain, but the outbreak is a publicity disaster for a company whose image has already taken a battering over recent years.

In 2005, the company's most notorious product, the Turkey Twizzler (pictured), came to symbolise everything that was wrong with British school dinners, and last year the company announced a drop in operating profits to £26.7m, from £40.4m the year before.

Conditions inside Bernard Matthews turkey farms were highlighted in September when two employees were secretly filmed playing baseball with live birds at a turkey shed in Haveringland. Both men admitted ill-treatment, but claimed they had been caught up in a "culture of cruelty" at the farm.

The allegations were rejected by the company, which issued full-page newspaper advertisements denying turkey abuse. But the episode underlined the gulf between Mr Matthews's public image as a tweed-clad poultry farmer with a broad Norfolk accent and the realities of a company that churns out more than eight million turkeys a year.

The foundations of Bernard Matthews's estimated £300m fortune were laid in 1950 with 20 eggs and a second-hand incubator.

The son of a mechanic, Mr Matthews was born in the Norfolk village of Brooke in 1930. His head for figures won him a scholarship at the City of Norfolk school, but he left at 16 and was working for an insurance company when he started looking for new ways to earn money.

"One day, at Acle market, there were 20 turkey eggs up for sale. I bought them for a shilling each. On the same day, in another part of the market, there was a small paraffin-oil incubator, which I bought for £1/10s," he said.

Only 12 turkeys from that batch survived, but once he had fattened them up, Mr Matthews was able to sell them for £9 - and his career in turkey-farming had begun. By 1960 he owned the biggest turkey farm in Europe, and four years later, Nikita Khrushchev sought his advice on the modernisation of the Soviet poultry industry.

During the 1980s, developments in food-processing allowed the company to develop new ranges, including Mini-Kievs, Turkey Dinosaurs - and the now-infamous Twizzlers.

Mr Matthews now reigns over a global business empire with an annual turnover of £400m, employing 7,000 people in countries as far afield as Hungary and New Zealand.

Although Jamie Oliver made it synonymous with unhealthy eating, sales of the Turkey Twizzler actually rose by a third before production was quietly stopped last year.

And when he was appointed a Commander of the Royal Victorian Order (CVO) in this New Year's Honours list, Mr Matthews may have thought that his luck was starting to change.