The number of alleged crimes potentially involving people’s use of dating apps Tinder and Grindr has increased more than seven-fold in the past three years – including reports of rape, grooming and attempted murder.

Experts said the findings were “shocking” and urged the authorities to launch a campaign to raise awareness of the dangers of meeting strangers on the so-called hook-up sites.

They said users were vulnerable to “sextortion” and warned the figures may be “just the tip of the iceberg” as many victims will be too scared or embarrassed to contact police.

Just 55 reports of crimes in England and Wales mentioned Grindr or Tinder in 2013, according to figures released to the Press Association under the Freedom of Information Act from 30 police forces. This jumped to 204 in 2014, and 412 in the year to October 2015.

Violent and sexual crime reports were the most common (Dominic Lipinski/PA)

Reports of violent and sexual crimes were the most common, with 253 allegations of violence against the person and 152 reports of sex offences, including grooming, rapes and the sexual exploitation of children.

The figures come from police reports where the apps are mentioned in the crime report and does not automatically mean the app was used directly by the criminal. But there have been documented cases in which they were.

Grindr is a gay dating app (Jonathan Brady/PA)

Deputy Chief Constable of Merseyside Police Andy Cooke, the National Police Chiefs’ Council’s lead on violence and public protection, said: “The rising popularity of online dating apps and websites has contributed to an increase in the number of recorded crimes.

“I would urge those who use online dating apps to be as security conscious as possible and not to share personal data with anyone until they are sure about those they are communicating with.”

Users have been urged to not share personal data with anyone until they are sure about the person they are communicating with (Lauren Hurley/PA)

Andy Phippen, professor of social responsibility in IT at Plymouth University, said it was a “growing problem, particularly around sextortion-type activities”.

He said: “If we are going to base the formation of a relationship on a photo and a few lines of text, how do we know that person is who they say they are and they have the right intentions?”

A spokesman for Stonewall added the figures are “shocking” and Victim Support said people using the apps should tell a friend where they are going before meeting anyone on the app.

Charities urge people using apps like Grindr to tell a friend where they’re going before meeting anyone (Jonathan Brady/PA)

The figures come from police reports where Tinder and Grindr has been used in the description of an allegation. This can refer to cases where they were allegedly used to commit a crime, where the victim and suspect met on the app, or where the app was mentioned but was not directly related to the crime – for example when a victim happened to be on Tinder when the crime was committed.

The forces which provided figures did not give a breakdown of the different situations.

Grindr and Tinder did not reply to requests for a comment.