"One report of indecent exposure is one too many," a railway chief has said amid a 62 per cent rise in cases on the National Rail network since 2019.

British Transport Police received more reports of exposure on the railway network in Hertfordshire than it did in the whole of Wales last year.

A Freedom of Information request to the force, sent by the Local Democracy Reporting Service, has revealed 183 reports of indecent exposure on trains across the country in 2023 – up from 158 in 2022 and 113 in 2019.

A total of 35 cases were reported on the Govia Thameslink Railway (GTR) network – which includes Great Northern, Southern and Thameslink routes in Hertfordshire.

A further 12 were reported on Greater Anglia routes and 10 on the London Overground which includes trains and stations in Cheshunt and Watford.

Most reports of indecent exposure were made with reference to routes in London and the commuter belt, the figures suggest.

Exposure is a crime which takes place when a person has intentionally exposed their genitals to upset or frighten someone else.

A British Transport Police spokesperson said: "You can report anything of a sexual nature, including rubbing, groping, masturbation, leering, sexual comments and indecent acts.

"You don't have to prove that it was a criminal offence or that it was committed intentionally, as our officers will investigate that.

"No incident is too small or trivial, and we will always take you seriously.

"Each report we receive provides us with valuable information which we can use to build a picture of an offender.

"Often it allows us to notice a pattern of offending behaviour and then take action.

"We want everyone to know that they can text us discreetly on 61016, whether something is happening to you at the time or has happened to you recently.

"Our control room can dispatch officers to a location if required, or put you in touch with an officer to speak at a convenient time."

Of the 183 reports made nationally:

nine came from Hertfordshire;

65 came from the Metropolitan and City of London police areas;

11 came from Kent;

10 came from Sussex;

eight came from the West Midlands.

These cases were linked with National Rail trains and stations, and the data does not include reports of exposure on other networks such as the London Underground or the West Midlands Metro in Birmingham and Wolverhampton.

In addition to the 35 cases reported across the GTR network, the British Transport Police linked 20 reports with Southeastern routes in London, Kent and Sussex.

Network Rail property and stations were also linked with 20 reports.

Great Western Railway, Northern and West Midlands Trains were each linked with 11 reports.

No suspect was identified after an investigation following 66 reports, but at the time British Transport Police responded to the FOI request in February 2024, 27 reports had resulted in a charge, summons or caution.

Mike Boyce, head of security and policing at GTR, said: "Indecent exposure is a crime and we take reports of this nature very seriously.

"We work closely with the British Transport Police (BTP) to tackle unwanted sexual behaviour on our network and would urge anyone that witnesses this kind of behaviour to report it immediately to a member of staff or to the BTP."

Mr Boyce added: "One report of indecent exposure is one too many, and we are very sorry to the victims that have been affected by an incident of this kind on our services."