The Department of Trade and Industry was yesterday urged to investigate the software company at the centre of a £6.2 billion upgrade of National Health Service computers.

Manchester-based iSoft is expected to publish its twice-delayed financial results this week after a turbulent year.

This month, commercial director Steve Graham was suspended after accounting irregularities were identified by auditors. Another unnamed member of staff was put on special leave of absence.

It followed the resignation in June of chief executive Tim Whiston amid criticism over delays to the project to put NHS patient records onto a central computer.

Labour MP Paul Farrelly (Newcastle-under-Lyme), following the situation, said the DTI should investigate the company.

"The original allegation was it was being too sharp by half in terms of the presentation of accounts and profits," he said.

"Those chickens have come home to roost because the new auditors have said there are concerns about accounting.

"It is important to signal to shareholders and the public that all our companies - particularly those quoted on the Stock Exchange - are run with best practice."

ISoft was not commenting in advance of the publication of its financial results.

The Department of Health said that it could not comment on the financial affairs of a sub-contractor.