Some Bernard Matthews turkey products have been cleared by the Food Standards Agency (FSA) to be released for sale.
Bernard Matthews was holding back the products at two sites
The company had been voluntarily holding the products at cold stores in Chesterfield and at Holton in Suffolk, where the bird flu outbreak took place.
The FSA had previously said there was a "remote possibility" the products contained meat from a restricted area.
The agency announced it has "sufficient information" to allow the products to be released into the food chain.
An FSA statement said: "The Food Standards Agency investigation has tonight gathered sufficient information to conclude that product held temporarily in the Bernard Matthews cold stores at Holton and Chesterfield does not contain meat from a restricted zone in Hungary, which would have made it illegal to enter the food chain.
"As a result, the Food Standards Agency has tonight informed Bernard Matthews that the meat products held voluntarily in their cold stores for the past 48 hours can now be released into the food chain."
The first consignment of turkeys after the government gave the company the go-ahead to resume operations arrived at Bernard Matthews' Holton plant on Tuesday.
The turkeys came from more than 50 Bernard Matthews farms around the UK which were unaffected by an exclusion zone in Suffolk.
Scientists have said the strain of H5N1 bird flu at Holton and that which infected geese in Hungary were "essentially identical".
Deputy chief vet Fred Landeg said the most likely transmission route for the outbreak was from poultry to poultry and that no evidence of "illegal" movements of poultry products has been found.
Bernard Matthews has stressed the FSA's reassurance that "avian flu does not pose a food safety risk to UK consumers and properly-cooked poultry is perfectly safe to eat".
Some 159,000 turkeys were culled after the H5N1 strain of bird flu was found at the Holton plant on 3 February.