Sequani is considering complaining to the Advertising Standards Agency over a leaflet put out by animal rights protesters in Ledbury, Hereford and Malvern.

Managers at the plant, off the Bromyard Road in Ledbury, say the leaflet contains "inaccurate and misleading statements" about animal testing.

At the heart of the argument is whether or not testing drugs on animals put humans at risk because the data cannot be relied on.

A Sequani spokesman said: "There is the statement, 'your health is at risk because of animal experiments, time and time again drugs are being withdrawn'. This is inaccurate in at least two particulars.

"Firstly, animal experiments are required by law to protect the safety of human volunteers and volunteer patients who participate in human clinical trials before a drug can be marketed.

"Secondly, withdrawal of drugs after they have been approved is, in fact, a relatively uncommon occurrence, and represents less than one per cent of new, approved drugs.

"In our view, the leaflet contains a number of inaccuracies and half truths designed to paint the valuable work we do in the worst possible light."

The 25,000 leaflets have been produced by a local protest group called Stop Sequani Animal Testing (SSAT).

Pauline Burgess, a Malvern-based SSAT spokesman, said the leaflet had been checked over by a solicitor before it was published.