SEX offenders living in areas including West Yorkshire are not being properly supervised, says a new report.
Police and probation watchdogs found the way officials keep tabs on perverts was "poorly co-ordinated and inconsistent". Even the handling of "very high" and "high" risk offenders needed to be improved.
The inspectors scrutinised sex offender management in Norfolk, Gwent, Merseyside, West Yorkshire and Devon and Cornwall.
Police make unannounced visits to sex offenders' homes to check up on them, but the frequency was lower than planned, it was found.
They planned to visit 3% on a weekly basis, but did not carry out any of these operations.
Most of the recommendations in a report published three years ago had still not been fully addressed.
Her Majesty's Chief Inspector of Constabulary Ronnie Flanagan said chief constables had been asked to ensure that only properly trained specialist officers were managing sex offenders in the community and that these officers received dedicated proactive supervision.