Four sex offenders have fled Oxfordshire and the UK and are being monitored by the British police, it has been revealed.

The information came to light as police released figures detailing the number of people in the county who have to sign the sex offenders register.

There are 310 registered offenders living in Oxfordshire - including one classed as at "very high risk" of reoffending and 57 said to be at "high risk" of reoffending.

Last October, 323 people living in the county had to sign the register.

Although the numbers have fallen, Det Chief Insp Tim Price, of Thames Valley Police public protection unit, said the number of sex offenders fluctuated throughout the year and many had simply moved out of the county.

Mr Price said the four missing offenders had failed to update their details on the register in the last 12 months and had gone abroad, but said they posed little danger to the public and officers knew where the four were living.

He added: "We do have ones who fail to sign on, but we track them down fairly quickly.

"Usually they have forgotten to sign or moved and not had time to pass on their new address.

"Although other countries do not have the same system as us we have intelligence to know where they are.

"If they return to the country they will be picked up by police because it is a crime not to notify a change in circumstances."

The figures were released to the Thames Valley Police Authority.

Of the 323 on the sex offenders register, 117 are classed as being at 'medium risk' and 135 classed as at 'low risk' of reoffending.

They are assessed by the Multi Agency Public Protection Arrangements (MAPPA).

The most serious offenders are tightly controlled, placed under surveillance, housed in a supervised hostel, given stringent reporting restrictions, banned from designated places or tagged.

None of those classified as at very high risk and high risk of reoffending have done so.

Police would not release the details of the missing offenders or the names of those on the register.

Mr Price added: "We can never guarantee 100 per cent offenders won't re-offend when out in the community, but our job is to reduce the risk and I am satisfied MAPPA works well.

"I can understand concerns of the public to why they should know, but we must balance that with the general public protection for everybody.

"If we compare us to the USA, which has a fairly open system, they have lost 50 per cent of their sex offenders and that puts everybody at risk."