John Redwood, the Conservatives' trade and industry spokesman, has demanded an apology from Mr Wills, who was appointed as an unpaid minister after the resignation of Peter Mandelson.
Mr Wills' television production firm, Juniper Communications, filed late returns twice and late accounts three times, according to Mr Redwood's research at Companies House.
The Tory spokesman raised the issue in the House 10 days ago. Mr Wills had said: "Every company with which I have been associated has filed its returns in compliance with the deadlines set by Companies House." Mr Redwood proceeded to list the occasions on which Juniper had not fulfilled legal requirements.
Yesterday, in a letter to the Conservative spokesman, Mr Wills said he believed the statement he made to the House was correct. He had been referring not to Juniper but to another firm he used to own. In a letter to Mr Wills last night, Mr Redwood called for a retraction of his Commons statement.