French steakhouse chain Buffalo Grill is contesting claims made by staff from its butchery arm, Districoupe, in a TV news interview, that 5-20% of the meat it processed during the British beef embargo between 1996 and 2000 had borne a UK stamp of origin.

The claims were originally made during interviews with French judicial officers at the beginning of February.

The group’s lawyers are questioning the validity of the interviews and are examining ways of lodging a complaint on the grounds of the subornation of witnesses.

Last week, the public prosecutor’s office announced it was in favour of annulling involuntary manslaughter charges against four of the group’s senior executives as a result of a lack of evidence linking the death of two people from vCJD to their eating at Buffalo Grill restaurants.

The news had led to a sharp rise in the group’s share price.

A Paris appeal court will deliver its verdict on 28 April. However, the prosecutor said the investigations into the other charges – endangering the life of others, deceit with regard to the nature and origin of goods and forgery and use of forgeries – should continue.