Some police forces have been under-recording the most serious violent crimes, the Home Office admitted today.

Official figures recorded by police in England and Wales show an increase of 22 per cent to 5,500 in the year to June compared with the previous 12 months.

The category includes serious assault, murder, attempted murder and manslaughter. 

Officials said 13 forces were asked to re-examine their figures after they discovered some serious assaults were being recorded in a lower category of offence.

The Home Office refused to name the forces involved but West Mercia Police said it was not one one of them.

Two of the most serious categories of knife crime also shot up after the miscounting was revealed. 

The number of attempted murders involving a knife rose by 28 per cent, while assaults causing grievous bodily harm with intent went up by 29 per cent.

The Home Office refused to name the forces involved – but admitted the under-counting could have been going on for more than 10 years.

West Mercia Police confirmed it was not one one of the 13 forces involved.

Det Supt Steven Cullen said: “We have robust recording and reporting procedures which are subject to regular internal review and audit.” 

Home Secretary Jacqui Smith insisted the increase was down to a statistical blip – and not to an actual rise in serious violent crime.

She said: “We revised offence categories for recording the most serious violence and clarified our guidance to police forces.”

Overall, recorded crime fell by six per cent to 1.22 million offences between April and June, 2008, compared to the same period the previous year.

Firearms offences also dropped by six per cent to 9,306 incidents and robberies by 16 per cent.

But there was an eight per cent increase in drug crime and an 11 per cent rise in fraud and forgery.

Parallel figures from the British Crime Survey showed crime the risk of being a victim of crime remains historically at its lowest level since the survey began in 1981.

However, it said people remain most concerned and threatened by teenage gangs hanging around on the streets, vandalism, drug abuse and dealing, and drunken and rowdy yobs.

By Sunita Patel