When you interview Olivia Lee there is bound to be a slight sense of nervousness. This is a woman who has made a TV career out of playing pranks on the unsuspecting, so as I sit down there is a temptation to look for a camera crew secreted behind the potted plant.

In the event, Lee — who first appeared in Channel 4’s Balls of Steel, starred in her own hidden-camera show, Dirty Sexy Funny, on the Comedy Central channel, and is now a regular on Jay Leno’s Tonight Show in the US —is not in pranking mode. In fact, she is nonchalantly nibbling on bar snacks in a break from an exhausting schedule which has taken her from Los Angeles to Australia. “You can write that I devoured the olive,” she suggests helpfully.

In the past, Lee has posed as a woman with obsessive compulsive disorder who invites a masseuse into her house but will not allow herself to be touched; then there is the hard-of-hearing American Jewish grandmother noisily slurping soup in a restaurant to the horror of a waiter, and the heavily pregnant woman whose waters break during an exercise class.

Very few actresses would have the confidence to pull it off. Lee, who grew up in Totteridge, north London, thinks she gets it from her family.

“It’s chutzpah. We all have it, don’t we? I think it’s because I grew up in a family full of very strong personalities. I could swear in front of my parents. They are liberal and were very young when my brother and I were born. So I was always outgoing and lively and pushing the boundaries.”

'We’re never mean and most people find it really funny. They are laughing with you and they are happy to be on TV. In fact, most of the time the joke is on me because I’m playing several degrees of crazy'

Despite this openness, Lee’s parents still wanted their daughter to follow a sensible career path, and she did… up to a point. She dutifully went to university to study business and marketing and found a job in an office.

“After a few months I realised it wasn’t for me. Luckily I was made redundant which meant I was able to pursue my dream, because it would have taken a lot of courage to leave the security of a regular paycheck.”

She enrolled at the Central School of Speech and Drama in London with the thought that she might become a serious dramatic actress. But that was not how it worked out. Her first job was on The Basil Brush Show. She was delighted. Her rather serious agent was less so.

“I was really proud because it was my first ever job. I would go into meetings and tell everyone I was doing Basil Brush but my agent kept saying: ‘Would you please stop telling people about that’. In the end she told me that perhaps I should get a different agent, so I did.”

Lee found she was offered plenty more comedy roles. She did a bit of stand-up but decided that character-based comedy was more her thing, and particularly the niche occupation of pranking the general public and the occasional celebrity (Boyband singer Antony Costa has the distinction of being pranked on two separate occasions by Lee).

It is a strand of comedy with an illustrious Jewish tradition. Paul Kaye was the first to confront celebs on opening nights posing as American showbiz reporter Dennis Pennis, and Sacha Baron Cohen developed it into art-form with Ali G, Borat and others. So was Lee aware of the Jewish heritage?

“Oh my God, I never realised,” she replies, adding cheekily: “I knew I was going to get something out of meeting you.”

She does think that there is something in the Jewish psyche that lends itself to being outrageous.
“On the whole we can externalise and get our feelings out there and get passionate about things. My ex-boyfriend was very English and he was always telling me to shush. He didn’t really understand the level of communication I have with my family.”

One place where her humour does seem to go down well is in the United State. Lee’s agent sent a tape of Dirty Sexy Funny to chat-show host Jay Leno and he called back the following day to with the offer of a job. She became a regular for a while, holding mock auditions to investigate just what people would be prepared to do to get themselves on TV. The answer? Practically anything. She also posed as a tour guide taking tourists around LA on a bus.

“We stopped at an STD clinic so I could get my results and I also stopped to throw a brick through a car — I told everyone it belonged to my ex-boyfriend. It was all quite inappropriate.”

Lee is well aware that the prank show format has a shelf-life. Because her face is now well-known, she often uses heavy prosthetics — either that or she acts abroad where she is less famous. But she is also branching out into writing.

She has completed a sitcom, although, because it has not been officially announced yet, she is coy about the details. What she can say is that it is set in north-west London and it is fairly autobiographical but is nothing like either Simon Amstell’s Grandma’s House or Friday Night Dinner.

“The Jewish community has been done a lot but not from a female perspective. It’s a really different story on the girls’ side. For example, my grandma would always say: ‘Sitcom, shmitcom – you’ll meet a man and get married and it won’t matter. What do you want a career for anyway, it’s so exhausting’.”

So will she be acting in the series? “Of course I will. You don’t think I’ve spent a year writing it just to give it to someone else?”

One imagines there must be a huge expenditure of nervous energy in Lee’s job, but she clearly loves the adrenaline and has had very few occasions when those who have been pranked have failed to sign the release forms to enable the clips to be used in her shows.

“I can be very charming when I want something from you,” she says. “Anyway, we’re never mean and most people find it really funny. They are laughing with you and they are happy to be on TV.

"In fact, most of the time the joke is on me because I’m playing several degrees of crazy. People usually don’t guess what’s happening. After all, the last thing they expect is that there’s going to be a whole camera crew hidden in the house.

"But if I think they suspect something I pull back and go in a different direction, or start behaving normally until I have their trust again. You develop an instinct for it after a while.”

She has plenty of confidence in her abilities but Lee has never come to terms with the chronic insecurity of her profession.

“Every day I worry about it. It’s got to the point that my friends, most of whom don’t work in showbiz, have told me ‘I can’t have this conversation with you anymore’. I remember finishing this job in LA and I was jubilant. Yay, I got my life back. The next day it was like, what am I going to do now? But then the day afterwards the phone rings. Something always seem to happen with me.”