The Care Quality Commission’s annual report claimed the regulator had carried out more than twice as many inspections as had actually taken place, the Mid Staffordshire Foundation Trust public inquiry has heard.

During this morning’s session, counsel to the inquiry Tom Kark QC said a new statement had been received from a CQC witness revealing that, rather than the 15,220 inspections the 2010-11 report referred to, only 7,368 were carried out.

The revelation came during questions to NHS chief executive Sir David Nicholson. Sir David did not comment on the figures directly but agreed physical inspections were at the heart of regulation.

Last week it was announced the inquiry had called new witnesses from the CQC after receiving an anonymous tip-off during the summer that called into question evidence from previous witnesses.

The inquiry heard evidence from the CQC witnesses, including chief executive Cynthia Bower and chair Dame Jo Williams, in May. The annual report was published in July.

A CQC spokeswoman said the mistake had been noticed in August.

She said: “This transcription error occurred in the preparation of statistics to go into the report. CQC realised the figures were incorrect in August and informed the inquiry immediately. It will publish an erratum shortly.”