A total of 112 sex offenders were reported missing in London
The number of registered sex offenders who are missing may have increased over two years, new figures suggest.
The figures, for three-quarters of the police forces in England, Wales and Scotland, were disclosed to the BBC after a Freedom of Information request.
Data supplied by 38 police forces showed 317 sex offenders were reported as missing or unaccounted for.
In January 2007, a significantly higher number of forces - 49 - reported that 322 sex offenders were missing.
The force reporting the largest number of missing registered sex offenders was London's Metropolitan Police, where 112 have disappeared.
Other forces with high numbers include the West Midlands with 34 missing, Greater Manchester which has 18, Kent with 13, Northumbria which has 12 missing and Sussex with 10.
Registered sex offenders are required to inform police and probation officers of their addresses.
A breakdown of the latest figures show 32 of the 43 forces in England and Wales responded to the request.
From a total of 31,069 registered sex offenders in the two countries, 304 were missing.
In Scotland, six of the eight forces which replied reported 13 offenders had disappeared from a total of 2,829 on the register.
The police service in Northern Ireland did not respond to the BBC's requests for information.
Figures collated by the News of the World newspaper in January 2007 did include Northern Ireland.
The Home Office came in for heavy criticism when the newspaper published its figures last year.
Child protection charities warned it was common for sex offenders to re-offend and the Conservatives blamed the government criminal justice databases for failing to keep track of offenders.