A film allegedly showing Norfolk farm workers being cruel to ducks is being investigated by the RSPCA and police.
The footage was secretly filmed at Hall Farm in Hingham and has "appalled" Waitrose, which has ended its relationship with the supplier.
Staff at Hillside Animal Sanctuary, near Norwich, mounted an undercover operation.
The owners of Hall Farm were unavailable for comment. Police said they had visited the farm.
A spokeswoman added: "Following a site visit officers are satisfied there are no ongoing issues of cruelty and police continue to assist RSPCA colleagues in their investigations."
The RSPCA said it was investigating after being shown the footage by Sky News.
A spokesman for Waitrose, which been supplied ducks by the farm, said: "We are appalled by the footage taken at Hall Farm.
"Following an immediate and detailed investigation, we have now ended our relationship with the farm.
"The behaviour seen on the film is totally unacceptable and completely goes against the high welfare standards Waitrose expects of its farmers.
"We are also reviewing our processes to make sure we do everything we can to ensure nothing like this can ever happen again."