Tim Burton is reportedly in a long-term relationship with Berenice Percival.

The 56-year-old director - who, last week, announced his split from Helena Bonham Carter after 13 years together - has been romancing the 39-year-old production assistant who has been working for him for three years, according to a report in The Mail on Sunday newspaper.

The blonde - who has been revealed as the mystery woman who was pictured embracing Tim last year after a cinema trip in Hampstead, North London - is believed to be a big factor in the separation.

Meanwhile, Helena's friends think Tim ''is having a classic mid-life crisis'' with the actress reportedly devastated that her efforts to save the relationship have failed.

A source close to the 'Alice in Wonderland' star - who has two children, Billy, 11 and Nell, seven, with the filmmaker - said: ''Tim is having a classic mid-life crisis. All Helena's friends think he's a terrible old cliche. Helena gave him a lot of time to sort himself out.''

Another pal also revealed that the actress is ''really upset'' about the split.

They said: ''Helena was very upset at the Chequers party earlier this month hosted by Samantha Cameron. Other guests noticed she was in a bad way.

''She is really upset. It's all still very raw and they only told the children two weeks ago.''