It's happened to the best of us - but it's hardly what you would expect from two celebrities with access to a stash of cash and expensive stylists.

Author JK Rowling and actress Anna Friel rocked up on the red carpet in the same flowing green dress - albeit worn in a slightly different way.

The multi-millionaire author of the Harry Potter books, and the former Brookside star attended a gala dinner at Hampton Court Palace on Saturday night, both wearing the dress. Rowling accessorised hers with a large emerald ring.

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Frock horror: Superstar author JK Rowling and Anna Friel have a red-carpet nightmare as they both turn up in the same dress

Magic meets politics: Harry Potter's creator JK Rowling with Mikhail Gorbachev

Decorated: A slick Sir Bob Geldof at the party

Both attended an event hosted by Mikhail Gorbachev, themed around a Russian midsummer fantasy, which raised money for the Raisa Gorbachev Foundation for sick children.

Miss Rowling, who wrote her first book in cafes as her young daughter slept, chatted and joked with the former Soviet leader. She obviously felt his was a cause worth supporting. She is a regular fundraiser for Russian charities.

Viscount Rothermere, chairman of the Daily Mail and General Trust, was in attendance with his wife Viscountess Rothermere, a patron of the event.

Harry Potter star Emma Watson, better known as Hermione attended the event and wore an unusual black and gold outfit.

A well scrubbed Sir Bob Geldof was also present, and he completed his sober black tie outfit with an array of medals for his charity work, as were Naomi Campbell and Elle Macpherson.

Other guests included Baroness Thatcher, also a patron, actor Ralph Fiennes, singer Rod Stewart and playwright Sir Tom Stoppard.

Dinner was followed by performances from Sir Elton John and the Scissor Sisters. Mr Gorbachev-whose wife Raisa died of leukaemia in 1999, spoke about how proceeds from the event would be used.

'Through the creation of the Raisa Gorbachev Centre of children's haematology and transplantology in St Petersburg, much needed medical care of an international standard will soon be available.

'Our efforts in this project give hope to many sick children and their parents.'

The foundation aims to finance projects such as the creation of a national bone marrow register in Russia, as well as supporting the families of those diagnosed with terminal cancer.

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Hermione's all grown-up: British actress Emma Watson (right) and Russian model Natalia Vodianova

Caprice and Naomi Campbell

Anna Matronic from the Scissor Sisters

Adding glamour to last night's charity event in aid of the Raisa Gorbachev Foundation: Kim Cattrall and Minnie Driver