A Metropolitan Police whistleblower has claimed crime figures are being manipulated by the force to meet City Hall targets.

Giving evidence to the Commons public administration committee, constable James Patrick said sexual offences were under-reported by up to a quarter.

The constable, who is awaiting disciplinary proceedings, claimed robberies were being incorrectly logged to get them "off the books".

Constable Patrick, who was involved in assessing crime levels, also said he found disparities between reports of burglary and those formally recorded.

He added that an audit revealed a significant amount of burglaries were re-categorised or downgraded.

Former Met Detective Chief Superintendent Peter Barron told the committee that statistical inaccuracies meant the number of officers in London boroughs was "grossly out of kilter" with demand.

The committee on Tuesday heard evidence of similar issues across the country.

The Metropolitan Police said in a statement that it was "committed to ensuring crimes are accurately recorded and has put in place robust processes to ensure crimes are neither over- nor under-recorded".

"The crime recording of sexual offences, and rape in particular, has been audited eight times in the period September 2012 to August 2013, and has achieved an average compliance across all six areas of scrutiny of 95%," it added.