Garbo's secrets to be revealed

Greta Garbo playing Mata Hari

A batch of letters written by legendary actress Greta Garbo - which are said to prove whether or not she had an affair with a glamorous socialite - will be opened by a US museum on Friday.

The 55 letters, 17 cards and 15 telegrams will be opened by the Rosenbach Museum and Library 40 years after they were donated by Garbo's close friend, writer Mercedes de Acosta.

Biographers and historians hope the letters will shed some light on the relationship between Garbo and Acosta, who donated the letters with strict instructions they were to stay sealed until 10 years after either her or Garbo's death.

On-off relationship

Acosta died in 1968, while Garbo - star of films such as Mata Hari and Anna Christie - died on 15 April 1990, after living as a recluse for nearly 50 years.

Mercedes de Acosta was close to Garbo for nearly three decades

The two shared an on-off relationship between 1931 and 1959, though its exact nature has been a matter of debate for historians.

Acosta claimed to have had affairs with Marlene Dietrich and dancer Isadora Duncan as well as Garbo.

But Garbo's family have doubted her claims, as have some of her biographers.

'Anything is possible'

Rosenbach librarian Elizabeth E Fuller said; "Garbo tended to be reserved in her correspondence, so we don't know what to expect. Anything is possible."

Biographer Karen Swenson said Garbo was a "fascinating letter writer".

"She loved language and loved playing with words and hiding behind words. Her letters were always interesting to her friends but weren't necessarily demonstrative of her feelings toward them."

Once opened, the letters - which have been kept in a sealed box - will go on show at the museum from 18 April until 4 June.