The eccentric pair, whose joint fortune is estimated at £80 million, even put on a united front for Christmas when they went for a stroll in London with their two children, Billy Ray, 11, and Nell, six.
But now The Mail on Sunday can reveal that Burton, 56, is already involved in a long-term relationship with Berenice Percival, a production assistant who has been working for him for three years.
The 39-year-old mother of one has been identified as the mystery blonde pictured in a passionate embrace with the Edward Scissorhands director last year after a cinema trip in Hampstead, North London.
She is said by friends to have been an important factor in the separation. Sources close to Bonham Carter and Burton said that the actress had fought to save their relationship.
One added: ‘She thought Tim was having a midlife crisis and gave him room to get it out of his system. But it never happened so she reluctantly decided to end things.’
The break-up has apparently divided friends in the film industry, many of whom have thrown their support behind the quirky 48-year-old actress.
Burton and Ms Percival, meanwhile, are believed to have been staying at a London house with her nine-year-old son.‘Berenice is telling friends that they’re happy, in love and that she sees a future with Tim,’ said the friend.
‘He has been caring and a lovely father figure to her son. She refers to Tim as her boyfriend.’
Ms Percival began working for Tim Burton Productions between late 2011 and 2012 after being introduced by members of Johnny Depp’s support team.
She had been an assistant on several of Depp’s films, including Charlie And The Chocolate Factory and Sweeney Todd, which were both directed by Burton and starred Bonham Carter.
Initially, Ms Percival dealt with basic administration but later began to arrange foreign travel for Burton and accompany him on business trips.
Their relationship took off when they travelled to Vancouver. ‘They were there for a few days,’ a source said. ‘They stayed out late and drank tequila.’
Another source added: ‘Berenice and Tim have just returned from San Francisco and will start shooting a new film in the New Year. It’s business as usual for them.’
When contacted by The Mail on Sunday, Ms Percival made no comment. Representatives for Mr Burton did not respond to our enquiries.
