The operative for Britain’s foreign intelligence service, who was in his 20s at the time, was sent on the spying mission to infiltrate Taliban and Al-Qaeda terror cells in Waziristan on the Pakistani border.

But before leaving, the agent completed a series of tests that reported his mental instability level as “the highest it is possible to score.”

The recruit “had more in common with a psychotic person than an average member of the population” and was “at risk of severe shock and trauma,” the test showed.

While in Waziristan, the agent, who had faced abuse as a child, witnessed the beheading of a family, with the event resulting in “vivid flashbacks and violent outbursts” upon his return to Britain.

The man murdered his child after arriving back home and was sent to a secure psychiatric unit until his trial.

He was paid tens of thousands of pounds for crucial information that he provided MI6 during his time overseas, his lawyer said.

However, Liam Kotrie, who is representing the recruit in court, said: “I believe they (MI6) got some intelligence — so for them, it was worth it. He was used. They thought they would get something from it — they ploughed money into the situation. They have a duty of care but they didn’t adhere to it and a child died.”

Kotrie said MI6 deliberately overlooked the recruit’s mental health issues to pursue information gathering.

The agent was convicted of murder in a jury trial, but his lawyer is seeking to overturn the conviction in favor of manslaughter.

“The (psychological) report said he was incredibly susceptible to PTSD but he was not aware of the diagnosis or his own vulnerabilities but he was put to work in these situations. Those people need to be held to account,” Kotrie said.

“I hope policies will change and that there will be policies in place when someone does something terrible as a result of work they do for security services that they think about the dangerous situations they put them in.”