A total of 34 sex offenders in the West Midlands are missing, police have revealed.
The figure is the second-highest amount in the UK, outside of London, which has 112 missing offenders.
West Midlands Police said the offenders could not be traced to their last-known address.
Claude Knights, director of children’s charity Kidscape, described the figures as “very worrying”.
She said: “I actually sit on a Home Office group which looks into the management of sex offenders so I am fully aware of some of the problems involved.
“But it is still a significant number of people who are missing and have breached their licencing conditions and obviously this is a cause for great concern.
“I think the problem is that some of them will have changed their address and will be in the middle of being processed so we do want to be too alarmist in this situation.
“However, the fact is they are off the radar and we have no way of knowing which level of offender they are and, more importantly, where they are so MAPPA have some questions to answer here as they are in the business of knowing where people are and how this has been allowed to happen is just not clear enough.
“It can lead to disquiet and unrest in some communities which everyone will obviously be very keen to avoid.”
Freed sex offenders are supposed to be monitored by officials of the Multi-Agency Public Protection Arrangements (MAPPA) which began operating in April 2001.
This body places a duty on the police and the National Probation Service to assess and manage risks posed by offenders in every community in England and Wales.
In the most serious cases MAPPA can recommend increased police monitoring, special steps to protect victims and the use of closely-supervised accommodation.
A West Midlands Police spokesman said the number of missing sex offenders would change as arrests were made and new information came to light.
But Khalid Mahmood, the Labour MP for Perry Barr, was unimpressed and called for an investigation into the missing sex offenders.
He said: “I am amazed that this could have happened at all. Not knowing the whereabouts of one sex offender is bad enough but 34 is unbelievable.
“The fact that there are 34 people out there of this calibre that are not tagged in anyway and cannot be traced is a significant breach of security. West Midlands Police need to get on to this as soon as possible before something goes wrong and they live to regret it.”
Last year it was revealed that West Midlands Police had lost track of the whereabouts of 25 sex offenders.