Kato remains in a coma.

Daijiro Kato remains in a coma following his accident in the early stages of Sunday's season-opening Japanese Grand Prix.

The former 250cc World Champion veered off-course and into an unprotected wall at over 200kph, just as he reached the braking area for the newly designed chicane, at the end of the lap three.

Both Kato and his RCV then cart-wheeled violently down the track for around 100m, before he came to rest, unconscious, in the middle of the circuit.

Kato's heart had to be re-started while he was in the ambulance on the way to the circuit medical centre. He was then flown to a local Hospital, where he remains in intensive care.

"He is still in a coma. Basically, there is no change from last night. He is getting round-the-clock treatment but has not regained consciousness," a Suzuka official told Reuters.

The cause of the crash remains a mystery, but countryman Tohru Ukawa has suggested he could have tangled with another rider, while in the close fight for fifth.

"It looked like he might have made contact with another rider. His bike just Jack-knifed and flipped into the air," said the fellow HRC star.

To date, no other competitor has suggested they were involved - although few have spoken publicly about the incident, but given the closeness of the racing in the early laps it seems certain that at least one rider would have seen the whole accident occur.

Troy Bayliss, Carlos Checa and Ukawa were among thosel near Kato at the time of the incident. Race officials have stated that TV footage and closed circuit cameras were unable to help determine what happened.

Regardless of the cause, Suzuka - a circuit built by Honda in the 1960s and considered one of the most challenging in the world - is under pressure to make more safety changes after redesigning the 130R/chicane section for this year. That followed the massive crash suffered by Alan McNish - at the 130R - in last year's F1 GP, where he bent the Armco barriers despite a protective tyre wall.

MotoGP rookie Marco Melandri broke his leg badly on Friday practice, while Aleex Barros damaged his knee when he hit a tyre wall in the morning warm up. World Champion Valentino Rossi also declared that some parts of the circuit were still too dangerous even before Sunday's race, although he didn't specifically highlight the area where Kato lost control.

Those demanding further changes are pointing to how close some unprotected walls are to the asphalt. The barrier Kato hit, although on a straight, was just 1.5m from the racetrack.

Many were also unhappy that the race wasn't red flagged, despite the obvious severity of the incident, and that the Suzuka marshals seemed too hasty to get Kato onto a stretcher, given what were clearly very severe injuries.

But the most important thing is Kato's condition and that remains critical. The 26 year old's family, friends, Gresini team and Honda officials remain at his bedside.