Something interesting about sex, or how to avoid the honey trap

I learned something interesting the other day about sex and the police force. Or rather, the UK police force. And then a story made the news which sounded like serendipity.
I bet you're all reading this because sex is involved. When I tell you the story, if you are outside the UK, maybe you could tell me if it applies to police forces around the world.
I stumbled across this information when I was researching my new crime thriller 'Or Else She Dies'. I have my main character Harry Chance, safecracker, jewel thief and former cage fighter, meet a woman at the seemingly unlikely venue of a bridge tournament (that's the card game).
Now, here's the thing. She is really an undercover police officer tasked with worming her way into his confidence, if not his affections and bed, in order to trap him into implicating himself in a series of jewel robberies and possibly a murder.
They form a relationship very quickly, so quickly that you wonder why Chance is not suspicious. But he's too taken with her to care.
She, in turn, is torn. Should she resign? This is where there appears to be a battle of loyalties. Her boss tells her that her behaviour is unprofessional and chief constable is on record as saying that this kind of thing is reprehensible for a serving officer. It could be a career ending situation.
Then her boss points to a recent statement by the policing minister that says it is acceptable for undercover officers to sleep with their suspects because it reinforces the bond and allays suspicion.
On the radio the other day, some politically correct minister said of a real life case like this that the officer should reveal his or her true identity because it might cause hurt and upset to the suspect.
Answers below please.