Eva Herzigova admits she was ''unbearable'' to work with at the height of her fame as a supermodel.

The 40-year-old Czech beauty has confessed she was ''irritable'' and would throw tantrums on shoots as well as display other unpleasant behaviour when she was known across the world for her famous ''Hello Boys'' Wonderbra campaign in the mid-90s.

But Eva insists the only reason she acted like a diva was because she was overworked.

Speaking to the French edition of Marie Claire magazine, she said: ''I was unbearable at one point and probably difficult to work with, but it was to do with exhaustion, trying to do too much. Going constantly from one plane to the next, from a fashion show to a photo shoot in a different time zone didn't help matters. I was irritable and had tantrums.''

Eva admits to ''losing'' a sense of herself at that time, but maintains she avoid many of the pitfalls of fame and the fashion industry such as drugs.

She explained: ''Losing myself, yes; going off the rails and taking drugs, no. My education has given me a strong will to resist temptations like drugs. They make you feel like the person that you want to be. But it's just an illusion. I used to see people get off their faces, and I was never interested.''

Meanwhile, the legendary model claims the secret to her happy relationship with long-term boyfriend Gregorio Marsiaj is that they work hard to keep the romance alive at home.

Eva - who has three sons, George, six, Philipe, two and five-month-old Edward, with Gregorio - explained: ''Such a long relationship, quite rare in our industry, it isn't a given. You have to work at it constantly, like a garden that you have to rid of weeds ... you have to communicate a lot, find time for both of us to be able to maintain the love, the romance, to appreciate the way things evolve.''