The Healthcare Commission spoke after the report by the Conservatives was published, which claimed that 70 per cent of NHS trusts had used pest controllers in the past two years.
The commission, responsible for monitoring hygiene in NHS buildings, said hospitals must minimise risk of pest infestations like flies, rats and cockroaches.
"We don't issue guidance that specific on composting, but we look at whether hospitals have risk-management systems and may check up on them," said a representative.
Newham Hospital in London, which installed a kitchen-waste composter last year, had a problem with large numbers of flies, said a representative for the hospital.
Initially, the problem was thought to have stemmed from the composter as it had attracted a large quantity of flies. The representative added: "It was stripped down, emptied, treated with insecticide and there was no sign of fly larvae. As the ultimate precaution we removed the composter in early November 2007."