The firm at the centre of a row over stockpiled hospital waste has confirmed it has ceased operations.
In its first public statement, Healthcare Environmental Services (HES) said all 400 staff were now redundant.
HES lost its contracts with NHS Scotland and 17 NHS trusts in England after it was found to be stockpiling clinical waste.
It is understood that HES workers have not received wages that were due on Friday. In a text message to staff on Christmas Eve it claimed the bank would not release the funds.
The firm has also said it cannot pay out redundancy money - and that payments would have to be claimed through the Redundancy Payment Service, a UK-wide scheme for employees of insolvent companies.
HES has blamed a UK-wide shortage of high temperature incineration facilities for the problems that led to its demise - a claim denied by the UK government.
In a statement, HES managing director Garry Pettigrew said: "We have tried so hard over the last few months to keep going but we've now reached the position where this is no longer tenable.
"Regrettably, we have informed staff that we are ceasing operations."
The company's main plant is at Shotts, in North Lanarkshire, but it has 10 regional centres across the UK.
Mr Pettigrew said he believed Transfer of Undertakings Protection of Employment (TUPE) regulations should apply, which would allow staff to transfer to a new employer on the same terms and conditions.
However, it was not immediately clear if this was the case.
In Scotland, the NHS is now dealing with clinical waste under contingency plans until a new contract starts in April.
In England Mitie has taken over some health service contracts previously held by HES.
Mr Pettigrew said: "We believe that TUPE applies here and we hope that the staff will have the opportunity to transfer to the new contractors appointed by NHS National Services Scotland.
"The contracts in England also fall within TUPE and Mitie and the other appointed contractors should allow this process to be implemented immediately to secure staff and customer services."
HES employees have claimed that large quantities of waste have built up at the Shotts depot.
The Scottish Environment Protection Agency (Sepa) said it was monitoring conditions at Shotts and at the firm's other Scottish site in Dundee.
Sepa issued enforcement notices on 12 September and 11 December, and on Friday said it was investigating whether criminal offences had been committed.
The Scottish government said it was working closely with Sepa and National Services Scotland to ensure waste collection and disposal services were maintained.
A spokesperson added: "The contingency plans include the provision of waste management services until the new national healthcare waste management contract commences on 1 April 2019."