Documents filed at Companies House state: “A main contractor has made a claim which is subject to a counter claim and has not been admitted and is in dispute.”
Harrington is also facing a £1.5m claim from a subcontractor which is also being disputed.
The document added: “The company has counter claims against each of these commitments.”
The claims are believed to centre on the Nova Victoria project where Mace is main contractor and Keltbray worked as a subcontractor.
PC Harrington Contractors collapsed in May when KPMG were appointed administrators.
The document confirms that unsecured creditors were owed £28m at the time of Harrington’s demise.
Some money has been raised by the sale of assets – including £1.9m from cranes – but the trade contractors are still facing a shortfall of £25m.