@Blossom64265
If the government knows the agent is abusing his position, his credentials should be pulled and he should be removed from duty. Poor behavior generally means a person is no longer considered worthy of security clearance. Revealing his identity might indeed endanger other agents and national security, but the government could issue a statement saying they are taking care of the situation.
As other have posted, MI5 'agent' means a CHIS.
If it was an employee, they wouid be described as an MI5 officer.
The abuse may well be utterly unrelated to the role for MI5. But of course the security services have to run agents who can tell them about shitty, criminal, dangerous things. Which means of course they have to deal with shitty, criminal, dangerous people
What I don't understand is how the role for MI5 is relevant to a court case - after all you can't just drag up anything and use it in court unless it has some relevance.
MI5 has a remit against serious and organised crime (not just national security in the sense of terrorism or spycatching) and so maybe the case is something to do with that? What I'm imagining is maybe someone who could report on trafficking, who was himself a trafficker.
A bit like IRA informers of old, where there was some tolerance of crimes because if they stopped their IRA activities (because MI5 couldn't have relationships with shitty, dangerous, people who were committing crimes during the time they were in touch) then there wouid be no information flow (as source would be cut off immediately if he became a non-participant).
But if you start looking at organised crime, then the range of likely offences changes, and we're just not used to thinking about that kind of 'how far can you go' in source protection if it's not terrorism.