The statement, which amounted to an apology, followed a report in yesterday's Independent over experiments by British scientists, who the minister claimed had examined the carcasses and found that the animals died of natural causes.
The scientists, at the Centre for Tropical Veterinary Medicine in Edinburgh revealed they had no record of the work being done.
Troops who served in the Gulf believe the animals may have been killed by pesticides or as a result of the use of chemical or biological weapons.
The Countess of Mar, a crossbench peer, had asked the minister last July whether there was any evidence that the dead animals had been exposed to nerve gas.
Earl Howe said in reply: "Samples from dead animals were sent back to the Edinburgh Veterinary School and Tropical Medicine Centre [sic] and all were found to have died of natural causes or such things as eating vehicle batteries."
Yesterday the minister told the House that the Ministry of Defence now doubted that this was true and that an investigation was under way to establish the facts. He said: "On Thursday last week I was telephoned in the House by a journalist who told me that his inquiries had led him to believe that my written answers to the noble Countess, Lady Mar, on 4th June and 5th July last year, about the deaths of animals during the Gulf War, were incorrect. I immediately set in hand an investigation.
"Early yesterday evening I received departmental advice that there is now considerable doubt over the accuracy of my answers. My Lords, this is a serious matter about which I felt it right to inform the House at the earliest opportunity."
The admission follows an apology in October by Nicholas Soames, the Armed Forces Minister, that he misled Parliament over the use of organophosphate pesticides in the Gulf. Lady Mar said: "How many more things are we being misled on? I remain absolutely convinced that chemical weapons were used on both sides."
She said troops who served in the Gulf had seen dead but unmarked animals lying on their sides as if they were asleep.
Lady Mar said that Earl Howe, who was clearly furious with his advisers, had personally apologised to her. She has been granted a meeting with the minister's advisers this afternoon at which she hopes to be given further information.Reuse content