The nine missing sex offenders from Northamptonshire are believed to be living abroad, a police spokesman has said.
Figures released by 39 forces under the Freedom of Information Act show 394 sex offenders in England and Wales are currently wanted because their whereabouts are unknown.
Registered sex offenders are required to keep in touch with their local force and inform them of any change of address so they can be monitored.
A spokesman for Northamptonshire Police said it took the management of sex offenders “extremely seriously.”
He said: “Of the nine sex offenders whose whereabouts are currently unknown, the vast majority are either believed, or known, to be living abroad - with a number having left the UK to return to their home countries.
“Changes in national legislation which came into force on Sunday, March 8, will make it possible for police forces to apply for orders to ban sex offenders from travelling abroad. It is hoped this change in the law will make the system even more robust.”