Kato was 250cc world champion in 2001

The 26-year-old Honda rider suffered serious injuries to the head, chest and neck when he was thrown off his bike after hitting a tyre barrier at Suzuka on 6 April.

Kato, who won the 250cc world championship in 2001, leaves a wife and two children.

"The whole team are close to his family in their time of grief," said a statement from the Telefonica Movistar Honda team.

"The team manager Fausto Gresini and several members of his staff will be flying to Japan for Kato's funeral."

Kato arrived on the world scene in 1996 when he finished third in the 250cc race at Suzuka behind Max Biaggi.

HAVE YOUR SAY Kato will be sadly missed by everyone. He was a great champion - words can not replace a great person Mike, Cheshire Send your tributes

He secured a grand prix ride in 2000 with Honda but missed out on the 250cc world title in the final race.

The world crown followed in 2001, however, along with new records for most wins in a season (11) and the highest points total in the class.

Kato's death is the first in the sport since another Japanese rider, Nobuki Wakai, was killed at the 1993 Spanish Grand Prix.

However, neither the Honda team inquiry nor the police investigation that followed the crash have been able to pinpoint its cause.

The team statement said: "Honda Racing has examined the motorcycle and analysed the available data regarding its operation, but found no irregularities.