Administrators of Cornhill are to investigate whether or not directors of the collapsed firm knowingly signed cheques that subsequently bounced.
A creditors committee has been specially formed to investigate how payments were handled on several of the firm’s contracts.
In one incident a cheque for £460,000 was signed to Woking Environments on two occasions and each time it bounced.
Bank statements will now be scrutinised and the remuneration packages of the directors checked over.
Joint administrator Colin Wilson said: “We will be looking at how the company was run and how payments were made, checking to see if any creditors were preferred over others.
“It is not to suggest anything inappropriate did occur, but it needs to be investigated.”
Concerns were raised in particularly by sub contractors involved in a £6 million office block development on Fenchurch Street in London.
The development ran into problems late last year after Cornhill said it was unable to pay a sub contractor.
The sub contractor then went directly to the developer Walbrook for payment which in turn led to the client withholding payment from Cornhill.
Directors of the collapsed firm were unavailable for comment.