Britain has started a criminal investigation into the build up of medical waste, including body parts, at a number of sites across the country.

Clinical waste is usually collected from hospitals and then destroyed but Britain's Environment Agency said in a statement on Friday that a contractor, Healthcare Environmental Services, had breached permits at five sites which deal with such waste.

"We are taking enforcement action against the operator, which includes clearance of the excess waste, and have launched a criminal investigation," a spokesman for the Environment Agency said.

Healthcare Environmental Services, which is headquartered in Lanarkshire, Scotland, and West Yorkshire, England, blamed the build-up on a reduction in Britain's high-temperature incineration capacity in recent years.

"All waste is contained and processed within licensed facilities in full cooperation with the relevant authorities," it said in an emailed statement.

The Department of Health and Social Care, said that body parts were a very small proportion of the waste in collection, and where there was "anatomical waste" involved it was being stored in refrigerated units at the sites.

"There is absolutely no risk to the health of patients or the wider public," a spokesman for the Department of Health and Social Care said.

"Our priority is to prevent disruption to the NHS and other vital public services and work is underway to ensure organisations can continue to dispose of their waste safely and efficiently."