POLICE have warned of a spate of online 'sextortion' and revenge porn cases in the county over the past two months.

The force has investigated 18 cases of online sextortion - blackmailing a victim by threatening to post intimate photos or videos on social networking, photo-sharing or revenge porn websites - mainly involving male victims, as well as five cases of revenge porn.

Two people have been arrested.

Dorset Police Director of Intelligence Detective Superintendent Mark Callaghan said: "The problem we have with locating the perpetrators of sextortion offences is the suspects will often hack in to other people's accounts and use a variety of methods to disguise their location.

"Most of the offenders are believed to be abroad in a variety of countries including USA, Ghana, Ivory Coast and the Philippines.

"We have, however, located and arrested two local offenders and more arrests are likely in the near future."

He added: "It is important that the public recognise the potential risks of their online behaviour."

A sextortion blackmailer can be an ex-partner or someone the victim has met on a social network or dating website.

Often they trick victims into revealing themselves on webcam, and the victim may not even know they are being recorded as the camera can be activated by spyware.

The perpetrators, often criminal gangs posing as individuals looking for romance, threaten to reveal the pictures unless they receive money from the victim.

Dorset Police said the gangs use "sophisticated technology" both to manipulate the images that a victim sees online and conceal their own identity and location.

The force is advising the public to carefully consider the potential outcomes before having intimate photographs or videos taken, even by trusted loved ones, and to avoid performing intimate acts in front of webcams.

DS Callaghan said: "However difficult it is, don’t be too embarrassed or ashamed to report sextortion, otherwise it will probably continue and others may become victims too."

Visit GetSafeOnline and cybersafe.dorset.police.uk for advice on online safety. If intimate photos or videos of you are posted online against your will, call Dorset Police on 101.