Taxpayers are being charged more than twice as much for medical waste to be removed from hospitals after the collapse of a scandal-hit firm, figures show.

Contractors are collecting more than £460,000 per week to dispose of the hazardous materials in Scotland following the demise of Healthcare Environmental Services (HES), according to a Freedom of Information request.

HES, which entered liquidation last month, removed waste from every hospital, GP surgery, dental practice and pharmacy in Scotland, as well as a number of NHS trusts in England.

Read more Backlog of clinical waste revealed at Lanarkshire health centres after HES collapse

It stopped collections in early December after too much waste including human body parts built up at its sites.

Former HES boss Garry Pettigrew has claimed the company charged Scottish taxpayers a maximum of £11 million per year - around £211,500 per week.

Hugh Pennington, emeritus professor of bacteriology at Aberdeen University, is now calling for an inquiry.

He expressed concerns about both safety risks and the value for money under the current contingency plans.

Prof Pennington, who led the inquiry into the 1996 E Coli outbreak in Wishaw, Lanarkshire, told the Press Association: "Waste is being generated 24/7 and has to be got rid of, safely as well.

"If what I've been told is true people are being put unnecessarily at a greater risk than they should be."

He went on: "If there is a doubling of the cost well that's something else an inquiry should look at, you know, 'what the bloody hell's going on here?'

"I don't know where the waste is going but I think there are great piles of it somewhere and that's a bad thing."

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Recent footage appears to show diggers tipping dozens of bags of medical waste into shipping containers and there are reports of waste now being moved around hospitals in open-sided containers "which could potentially expose those who are moving them to needle-stick injuries", Prof Pennington said.

HES stopped trading in December and laid off hundreds of workers after being found to have breached its permits by storing excess waste on its sites.

But Mr Pettigrew has maintained the build-up was because of a lack of incineration capacity in the country.

He labelled the contingency a "shambles" which is "putting lives at risk" and said he welcomes a public inquiry into the collapse of the company which operated for 23 years.

Under contingency arrangements, figures show around £7 million was spent in just 15 weeks - equivalent to around £465,000 per week.

Some £4.8 million was spent on "operational and logistics" costs and £2.2 million on "disposal" between December 5 and March 20, according to a Freedom of Information request of National Services Scotland (NSS) which provides services to NHS Scotland.

NSS did not break down specifics like tonnage or transport prices "as that could be used to establish individual pricing from the companies providing those specific areas which we assess to be commercially sensitive and part of a company's competitive strategy".

Emails from January between NSS officials seen by the Press Association show staff discussing waste contingency and the "significant increased cost compared to previously".

Correspondence also shows some GP practices did not have any collections for nearly a month between December and January and "now have lots of bags of smelly waste lying in corridors or stored in cupboards etc which is unacceptable and also a hazard."

Prof Pennington added: "On the face of it it does sound as if there wasn't a contingency plan that was going to deliver value for money and there was a contingency plan that certainly wasn't as safe, from what I've heard, as the work that was being done before.

"If it's costing twice as much, if that's correct, then the public is being put at a disadvantage."

The new waste disposal contract for Scotland has been awarded to Tradebe Healthcare National and is due to commence on August 2.

Read more Scots company at centre of criminal probe over body part stockpile

A Scottish Government spokeswoman said: "The Scottish Government provided £1.4 million towards initial planning and once the contingency period ends the exact cost of these arrangements can be finalised.

"Procedures followed for clinical waste collection in hospitals are unchanged since HES ceased operating.

"All agreed contingency measures ensure that the environment and human health are appropriately protected.

"Scottish Environment Protection Agency (Sepa) is continuing to monitor the operation of these arrangements and to date their inspections have not identified any risk to human health or the environment.

"NSS continues to work closely with NHS Health Boards, contractors, Sepa, and the Scottish Government to deliver robust contingency plans to ensure NHS Scotland services to the public are maintained and patient services are not impacted."