Jessica Chastain is to play the late Princess Diana in a new movie.

The 'Help' actress will portray the iconic royal - who died in a car crash in August 1997 - in 'Caught in Flight', which will be based on a real-life affair Diana tried to keep hidden.

The movie - which will be directed by Oliver Hirschbiegel - will revolve around a love affair between Diana and heart surgeon Dr. Hasnat Kahn, who was said to be the love of her life.

The couple met at London's Royal Brompton Hospital in 1995 when she was visiting a friend who was recovering from heart surgery and they embarked on a quiet two-year relationship.

Hasnat - who was nicknamed "Mr. Wonderful" by Diana - didn't speak about the princess until 2008, when he revealed their romance was so serious, Diana was considering converting to Islam.

According to the Thompson on Hollywood blog, the film is set to shoot in a number of locations, including Pakistan, Angola, the South of France and Paris, where the Diana died in a car crash with her lover at that time, Dodi Al-Fayed.

Before meeting Hasnat, Diana was married to Prince Charles and they had two sons, Princes William and Harry.