In a statement, the Met Police said: "The Metropolitan Police Service is committed to ensuring crimes are accurately recorded and has put in place robust processes to ensure crimes are neither over nor under recorded.
"The MPS has a centralised crime recording unit that has no performance measures in relation to crime figures."
The Met Police added: "The MPS has a monthly audit program that monitors those areas of crime that are under the most scrutiny (burglary, criminal damage, robbery, theft from or of a motor vehicle, theft from person, violence with injury)."
After raising his concerns with the Met Police, PC James Patrick was moved into a specialist role at territorial policing HQ looking at the measurement of crime levels. He found disparities between numbers of burglary reports and those finally recorded:
Burglary is an area where crimes are downgraded or moved into other brackets, such as criminal damage for attempted burglaries, or other types of thefts.
They were showing in some reports... a 400% increase in street robberies. If you looked at the same reports a couple of days later, robberies would be static, but theft snatch would have increased by a large amount.
MPs have been told that police officers are massaging crime statistics to improve performance figures. A serving officer, with experience of the way the Met Police produces statistics, says offences including rape and child sex abuse are being recorded as "crime-related incidents" or "no crimes".
Met Police Constable James Patrick, who is currently awaiting disciplinary proceedings, said he became concerned after joining the force in 2009 and finding robberies being logged as "theft snatch" in order to get them "off the books". He said:
"The extent of this in the borough I was initially in was large."