The number of sex offenders under supervision in West Yorkshire has increased to 1,467.

Police and probation teams are monitoring an extra 41 sex offenders in the region this year, compared to last year.

As of March 31 there were 189 registered sex offenders in Leeds North West, 172 in Leeds North East, 164 in City and Holbeck, 287 in Kirklees and 217 in Wakefield.

Freed violent criminals and sex offenders who "pose a risk of serious harm" are monitored under Multi Agency Public Protection Arrangements (MAPPA).

They receive one of three levels of supervision: level one is management by the police, probation service or other agencies; level two is for high or very high risk offenders supervised by more than one agency; and level three are those assessed as having the highest risk of harming the public and who are under the strictest monitoring by panels of experts.

The figures revealed that 115 sex offenders and violent criminals in West Yorkshire were returned to prison last year after a breach of licence- down from 144 in 2007/08.

They included six level three or so-called "critical few" offenders.

Another three offenders were sent to prison for breaching sexual offences prevention orders, while 28 sex offenders who had a registration requirement were either cautioned or convicted of failing to register.

One sex offender was charged with a serious further offence, while two violent offenders were convicted of further offences.

An introduction to yesterday's report written by West Yorkshire police and probation bosses stated: "Despite the careful risk management, skills and commitment of staff, no system can provide a 100 per cent guarantee that an offender assessed as dangerous can be prevented from committing another crime.

"More than 99 per cent of offenders under supervision will not go on to commit a serious offence, but tragic cases will still occur, despite the best efforts of staff."

But concerns were yesterday raised that the increase in supervised sex offenders is putting extra pressure on police.

David Ruffley , the shadow policing minister, said: "The increase in the number of sex offenders being registered is a sign of progress but it also underlines the need to allow police to do their jobs.

"As a result of this worrying trend there will be pressure on police time to keep an eye on these offenders in local communities. That is why it is all the more important to cut the amount of police time wasted on unnecessary bureaucracy."

Those on the sex offenders' register are required to notify the police if they change their name or address and some have to say if they plan to travel outside the UK.