SCOTLAND's most senior ­prosecutor has called for a specific law to target those who post "revenge porn" online.

Lord Advocate Frank ­Mulholland said he believed "bespoke legislation" would make it easier to pursue criminals, mostly men, who seek to publish intimate images to humiliate former or current partners.

His call came amid concern from Scottish Women's Aid and Rape Crisis Scotland that videos or stills are increasingly used to bully, harass or control women. There are also particular fears teenagers of both sexes are facing humiliation on social media.

Mr Mulholland said his ­prosecutors were able to pursue some offenders using laws designed to tackle stalkers or ­telephone crimes, or even breaches of the peace.

However, he added: "There is no bespoke offence covering revenge porn. We have been using existing legislation. That is not always satisfactory. We have had some successful prosecutions but I would support any call for bespoke legislation to deal with it."

Some states in America - where the crime first emerged - have introduced special laws against revenge porn, as have Brazil, Israel and the Australian state of Victoria.

As the law stands, it is illegal to publish indecent pictures of minors. But it is not a specific offence of putting a photo or video of an adult online without their permission. There is no special protection against the publication of intimate images, even if they were made for private use.

Victims can use civil action to have their pictures taken down from the web, but this can be very difficult, as websites - which can generate thousands of dollars in advertising revenue - may be hosted in hard-to-reach jurisdictions.

Mr Mulholland stressed the difference between civil action to take pictures down and criminal prosecution.

He said: "We can and do ­prosecute this crime robustly. However, it is a growing problem and specific legislation would send a signal to those who do this that they face jail.

"There have been five ­successful prosecutions in Scotland under existing legislation, however it is important that the issue be considered by the Scottish Parliament.

"I believe there is significant under-reporting of this issue, possibly because those affected are too embarrassed to come forward or fear they will be blamed."

Sandy Brindley of Rape Crisis Scotland welcomed Mr Mulholland's remarks.She said: "It is really important that the law gives out a strong message that this type of behaviour is criminal and has clear sanctions for it. Revenge porn is often used in the context of domestic abuse or sexual violence."

Nationalist MSP Christina McKelvie said she believed there was cross-party support for new law. "This is a new crime and needs new legislation," she said.

The Scottish Government said it would give the matter careful consideration. A spokesman said: "The protection of victims is at the heart of how our justice system operates. There is no doubt that there may be advantages to the creation of a specific criminal offence relating to revenge porn."