Slade's accident occurred when his seven-year-old mare, Kinchella, hit the first part of a double at The Farmyard (fence 17 on the intermediate course) and, having deposited his rider on the ground, fell on top of him. The Australian, who was immediately attended by the event doctor, died later in Salisbury District Hospital from severe head injuries.
When he first came to this country three years ago, Slade was based with Matt Ryan - a fellow Australian and winner of the individual gold medal at the 1992 Olympic Games. Slade had moved to a yard in Oxfordshire when he competed at Badminton for the first time last month.
Under the atrocious conditions that prevailed on the Gloucestershire course after torrential rain, Slade had been delighted to finish in 28th place on Beauford Miss Dior. He had owned the 11-year-old mare jointly with his parents, who live at Beauford Park in Williamtown, New South Wales.
Jane Holderness-Roddam, newly elected chairman of the British Horse Trials Association, said: "On behalf of the whole sport, I would like to extend our deepest sympathy to Robert's family and his many friends both here and in Australia."
Slade is the 14th rider to sustain fatal injuries at a British event since April 1982. Prior to Beckett's death, the last previous fatality occurred at Blenheim in September 1997 when the Irish rider, Sam Moore, died after his horse fell on him.