The government should criminalise "upskirting" as a sexual offence, say campaigners, after police data showed one complainant was 10 years old.

The practice of covertly photographing under the skirts of women is not recognised as a specific offence.

There have been just 11 charges related to upskirting since 2015, a Freedom of Information request found.

But only 15 out of 44 police forces contacted held records and it is feared the number of offences is much higher.

Currently police charge alleged "upskirters" with other offences.

MP Maria Miller, who chairs the women and equalities select committee, said more must be done to stop the "horrific crime" of upskirting.

She said: "Attempting to take a photograph underneath a skirt is a gross violation of privacy and potentially an act of indecency".

Ms Miller added that a stronger legal framework "can help" begin to tackle the problem.

Law 'not fit for purpose'

As there is no law specifically naming and banning the practice, victims and police are presently only able to pursue offences of voyeurism or indecency.

The FoI requests, made by the Press Association, found the police pursued 78 offences related to upskirting since 2015, but only 11 led to alleged offenders being charged.

There was insufficient evidence to proceed in several cases, including in regard to an alleged sexual offence on a 10-year-old girl in 2015, Avon and Somerset Police said.

Upskirting took place in a wide variety of public spaces, including nightclubs, shops and restaurants - with mobile phones frequently used and young women disproportionately targeted.

Clare McGlynn, professor of law at Durham University and an expert on sexual violence, said the FoI data showed there "are few public places where women are free from this abuse".

She said: "The government's continuing failure to provide an effective criminal law against upskirting breaches women's human rights."

She added women were entitled to protection, privacy and "a law that is fit for purpose", by treating the act as sexual abuse and providing anonymity to complainants.

"Only then will victims feel more willing to come forward and report to the police and support prosecutions," she said.

Police 'clearly struggling'

Campaigners say the current situation resembles that of revenge porn: the practice of posting online explicit material without the subject's consent, which was only made illegal in April 2015, after a national campaign.

They argue the ambiguity surrounding upskirting is similar, and that a specific offence needs to be created so the police can pursue more cases.

Sarah Green, for the End Violence Against Women coalition, described the police figures as "very concerning, even though only a minority of police forces were able to respond because the behaviour is not classified as an offence".

She said: "The police responses show that the police are clearly struggling to recognise upskirting distinctly, even though the disclosures reveal that it is commonly connected to existing sexual offences including voyeurism and sexual assault.

"It is notable that girls and young women are disproportionately targeted where that information has been recorded. The law should be urgently examined in this area."