London (Reuters): Britain's Prince William and his brother Harry recall memories from their childhood 20 years after the sudden death of their mother, Princess Diana , in a new television documentary to be broadcast this week.

The 90-minute film - "Diana, Our Mother: Her Life and Legacy" - celebrates the life and work of Diana, Kensington Palace said in a statement.

Diana, the first wife of heir to the throne Prince Charles, was killed in a car crash in Paris in August 1997 when William was aged 15 and Harry was 12. She was 36.

In the documentary, William - Queen Elizabeth's grandson and second in line to the throne - and Harry are filmed talking about their childhood as they look through photographs in a family album assembled by Diana.

Earlier this year, William spoke about how the shock of losing his mother still lingered two decades after her death . Harry said he had sought counselling to help deal with the grief.

The film , made by Oxford Film and Television, will air in the UK on ITV (ITV.L) on Monday at 2000 GMT.

A number of commemorative events have been planned to mark Diana's death .

William and Harry attended a private service earlier this month to re-dedicate her grave and the brothers have also commissioned a statue to be erected in her honor outside their official London home.

Rarely-seen possessions of Diana, including her music collection and ballet shoes, went on display on Saturday at Buckingham Palace.

An exhibition celebrating Diana's fashion opened in February.