Healthcare Environmental Services (HES) ceased trading after being caught up in a row over stockpiling medical waste with the NHS last year, laying off hundreds of workers around the UK last December.
MSPs were told of a backlog of between 250 and 300 tonnes of clinical waste and 10 tonnes of anatomical waste at Scottish HES sites in Dundee and Shotts, North Lanarkshire.
• READ MORE: HES collapse: Waste firm ceases operations after backlog controversyHES liquidator BDO said work has now begun to clear the backlog of waste at Shotts after a contract was agreed with Cliniwaste Ltd.
A BDO spokesman said: "The joint liquidators have agreed a licence with Cliniwaste Ltd to operate the Shotts, Newcastle and Nottingham sites.
"This agreement provides an option to purchase after three months.
"As part of this licence, Cliniwaste Ltd is already on-site clearing waste."
HES had removed waste from every hospital, GP surgery, dental practice and pharmacy in Scotland, as well as a number of NHS trusts in England.