Tulisa Contostavlos has revealed that she carries the phone number of a female private detective on her mobile.

The N-Dubz frontwoman has also admitted that she wouldn't hesitate to employ her to spy on and sleep with a boyfriend to test his fidelity.

The singer said: "Because I know nearly all men cheat, it makes it hard for me to trust them and I'm very jealous. I would quite happily pay someone to go and shag my man, record it, and if they gave me evidence, I'd pay them £1,000."

Contostavlos has explained previously that life on the road with N-Dubz has only reinforced her opinion that most men are cheats. 

The N-Dubz singer would go one step further with a fiance: "When I get married, I will 100 per cent do a lie detector test with him and ask if he's ever cheated." 

N-Dubz's new single 'Best Behaviour' is out today. Watch the video below: