Oliver Tobias, wearing an apron and carrying a tray covered with a white cloth, looked unrecognisable from the bed-hopping Tony Blake of The Stud and less still like the tanned hero, Prince Hasan, of EMI's current Arabian Adventure. Which should please him a lot, for he abhors the thought of being typecast in one particular mould, no matter how romantic.

I was watching him on location at a factory in Chiswick, West London, for scenes in his latest film, A Nightingale Sang in Berkeley Square, a comedy based on the true story of the world's biggest robbery - 30-million dollars from a major American bank in Mayfair. Oliver's co-stars include David Niven as the mastermind known as Ivan the Terrible, and Richard Jordan who plays a petty croook named Pinky Green who is involved in the robbery.

"Foxy, the character I play, is basically fairly straight," Oliver told me. "He peddles hot dogs and hamburgers from a stall in Leicester Square. He's done a few small crimes but he's a friend of Pinky's and gets caught up in the events of the bank robbery and reacts straight down the line. It's a nice part.

"To put a part across, I rely on the situations and  surroundings, the actors and film technique. The director is the catalyst between the actors and the camera crew. Ralph Thomas, who's directing "Nightingale", has the whole thing in his head. Making a film is an ideas game, using your imagination, how to take the script off the page. The scene I'm about to do with Richard Jordan is improvised, and lots of lovely things spring out of that. I'm more into atmosphere when I'm working on location, as on this film."

"Are you a physical actor?" I asked Oliver, remembering how tough many of his portrayals have looked on screen.

He pondered my question before replying : "Everything depends on the part. I ride horses and fence. It helps to make you physically aware and to think professionally. I attended the East 15 Acting School. I worked very hard at drama school. You come away with an idea of professional training which I think is very good because you can expand yourself, learn about other people, and find out more about yourself. It's a neverending process. It takes a special kind of energy for films as there is no audience to carry you through and make it work."

I asked Oliver if it had always been his intention to become an actor since his schooldays. Surprisingly, the answer was a negative shake of his head.

"I wanted to fly as a kid," he told me. "It was my ambition to be a fighter pilot. At school I played Edmund the Bastard in "King Lear" as my end-of-term play, and when a career in aviation didn't materialise, I chose acting as my work. You have to have a dedication to the profession, or you are doomed to fail."

Like many actors, Oliver's background is a cosmopolitan blend of several European cultures. "I was born in Zurich and still hold a Swiss passport," he explained. "I speak a number of languages and have travelled about a good deal from an early age. I was brought up in Switzerland, Austria and Germany. My mother was German, and my father Swiss. They ran a touring company which did about two plays a year in Munich and Zurich. My mother was the first woman to play Mephisto in "Faust". My father (Robert Freitag) directed the plays. I left home at ten and went to boarding school in England.

"My first film after leaving drama school was
Arthur? Arthur! with Donald Pleasence, which was never released. Then I went to Yugoslavia for my second picture, Abraham Polonsky's Romance of a Horse Thief, which starred Yul Brynner. After that came Tis Pity She's a Whore, with Charlotte Rampling, in Rome. Four years ago The God King took me to Ceylon (Sri Lanka) for several months with Leigh Lawson. It was not commercial, but millions of Indians knew the legend."

"You played leading roles in Hair and Jesus Christ Superstar on the stage?" I prompted.

"I had a long experience with both shows," Oliver replied. "I spent seven weeks in Israel directing and choreographing Hair in Hebrew, which I don't understand, but it was very successful. I was twenty when I played Berger, the second lead, at the Shaftesbury Theatre in London. Later, I was asked to choreograph the show in Holland. From there, I went to Tel Aviv to stage the Israeli production. I have also played Judas in Superstar in the German theatre.

"As an actor, I find theatre is more satisfying although I love making films. You must always have concentration, and find your own energy level. A film is made out of sequence and you have to rely more on the director and the script.

"When I'm working on a film, I always watch the "rushes". It's the only way to shape and hew your performance. I think this is essential for any actor. In Arabian Adventure I have a six-minute fight scene. There are flying carpets chases, and love scenes with the Princess (Emma Samms). It's a very exciting fantasy film, and I enjoyed making it."

At 31, Oliver is six foot tall and darkly handsome with the type of brooding eyes that women fall easily in love with. He's still unmarried and has no shortage of female companions but, unlike many of the lusty characters he plays on screen, he prefers to remain a one-girl guy. Travel and sailing top his list of relaxations, as well as music and playing the guitar.

"After playing the role of the Zealot in Franco Zeffirelli's TV epic Jesus of Nazareth, I took some time off," Oliver concluded. "Actually I had inherited some money, so I didn't work for two years. My first job after that was The Stud opposite Joan Collins, so I really fell on my feet. Even today, people never give up asking me about it. That film certainly came up trumps for me, but I was determined to go in a different direction next time.

"That's why I want to show people that I'm an actor, not just a sex symbol. So I'm taking as many varied parts as I can, such as Prince Hasan in Arabian Adventure and now Foxy in A Nightingale Sang in Berkeley Square."

With the way his film career is enjoying such a healthy upswing - what more could this modern Oliver ask for ?