A convict landed in hot water when his own son shopped him for having sex with his girlfriend during a family visit to prison.

Media outlets have reported that a 30-year-old inmate at Sudbury Prison, who has not be named, was caught with the woman in the visitor toilets at the open prison.

But the jailbird, who is serving five years for robbery, was only busted when one of the couple's two kids raised the alarm. It is claimed the youngster spoke to supervisors and said, "I can't find mummy and daddy".

After facing the governor on charges of "improper behaviour on family visits", three separate punishments were handed out to the man.

The Sun reported the lag was fined half-a-week's wages, banned from having visitors for three months and stripped of his gym privileges.

The publication reported the visit, which took place on September 1, left HMP Sudbury on full lock-down while wardens searched for the missing prisoner.

A Prison Service spokesperson said in a brief statement: "A full investigation of this incident is under way."

A source at the jail told The Sun: "The staff had their hands full with the children and didn't notice the man and his girlfriend had disappeared. It was only when one of the children said they couldn't find their mummy and daddy that the alarm was raised."

The British prison service does not permit conjugal visits, unlike a host of other European countries, including Denmark and Germany.

In 2016, UK Secretary of State for Justice Elizabeth Truss told MPs that the sex-on-visitation policy was unlikely to change any time soon.

She said: "I'm not entirely of favour of the 'Danish Approach' put it like that. I won't include that."

A year earlier, British authorities were forced to launch a probe after multiple reports surfaced about prisoners allegedly having sex with partners in full knowledge of guards.

In one instance, a prisoner was allegedly given half an hour to have "birthday sex" with his model girlfriend.

Another saw at least three guards reportedly turn a blind eye as a convict had sex several times while in an NHS hospital.

Conservative MP and Prisons Minister Andrew Selous said at the time: "We've opened an urgent investigation into these allegations. If proven, the public will rightly be shocked. If individuals have failed in their duty, they will face the strongest disciplinary penalties."

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