Judicial authorities in Belgium are investigating the crash at yesterday’s Tour of Flanders in which Garmin-Sharp rider Johan Vansummeren hit a 65-year-old female spectator at speed.

According to Flanders News.be, both the rider and race organisers could face prosecution if investigators decide there is a case to answer. But a sports lawyer says that while he believes Vansummeren should bear no responsibility, there could be a case against both the unfortunate victim, and the Flanders Classics organisation.

The woman, named by Het Niuewsblad as Marie-Claire M., underwent two operations on her brain yesterday, and remains in an induced coma in a hospital in Kortrijk. Her condition is said to be stable but critical.

The collision happened as the peloton sped past a traffic island where she was standing, along with other spectators, around 60km into the 259km race on Stationsstraat in the town of Wielsbeke.

Vansummeren is believed to have seen the obstacle too late and apparently tried to bunnyhop it, but could not avoid hitting her.

Video footage shot by a fan across the road on a cameraphone and posted to YouTube showed her being knocked of her feet by the force of the impact, and it is understood that she hit her head on a kerbstone.

The rider, winner of Paris-Roubaix in 2011, was also taken to hospital but discharged in the afternoon with facial stitching and a black eye.

Understandably, he was distraught about the incident. “My situation is not my main concern now,” he told the press. “I am more worried about the lady.

“I never wanted this to happen. This could have been a beautiful day, but it turned out to be a nightmare. My thoughts are with her and her family."

At the early stages of an investigation, Belgium adopts an inquisitorial system in which a court, or person acting on its behalf, compiles a dossier into an incident to determine whether there is a case to answer.

That the judicial authorities are carrying out an inquiry into what happened yesterday is therefore nothing out of the ordinary; it would be comparable to a police investigation in England & Wales.

"Was the lady allowed to stand there? Or was it the rider that made the wrong manoeuvre? We have to investigate all this, using the accounts of witnesses, the statements made by Mr Vansummeren and the amateur video that you have probably seen", explained Tom Janssens on behalf of investigators.

It is reported that they will also examine how much warning the riders had been given of presence of the pedestrian island.

He added that it would not be an easy incident to investigate, since it took place while the competition was underway, between the lead car of the race and the green flag signalling the end of it.

“In that case, specific rules apply,” he said.

Following the incident, some people on social networks such as Twitter queried why there was not a flag marshal at the location to warn riders of the hazard.

One reason is may be that the sheer volume of road furniture on the route of the race means it would be impossible to station someone at every single potential obstacle.

However, a Belgian sports lawyer told Brussels-based French language newspaper Le Soir that while he believed Vansummeren was blameless, the spectator and race organisers could both be found liable for causing the incident.

"In legal terms, Vansummeren did not commit an offence," explained Jean-Pierre Deprez, who is based in Charleroi. "It's the same same principle that applies to accidental wounds and injuries. His aim was to get from Bruges to Oudenaarde as quickly as possible . Many crashes happened during the race.

"I'm thinking of [Trek Factory Racing] rider Yaroslav Popovych who fell heavily and abandoned hitting a spectator with his handlebars. In my opinion, the riders have no responsibility for this. But if Johan Vansummeren had taken a shortcut to save time and he knocked down a spectator, of course it would have been his fault."

Asked who's fault it was, the lawyer replied: "In my opinion, the liability of the woman could be criminalised. She was situated in an insecure location in the middle of the road where the group goes at more than 50kph, very close to the spectators.

"She put herself knowingly in danger in what is termed the theory of risk acceptance. Like in rally racing, spectators sometimes take unncesessary risks to enjoy the fleeting moment. But the woman cannot assume sole responsibility."

Questioned whether he was referring to the race organisation, he said: "Very clearly , yes," citing a Belgian law of 1967 relating to bike races that requires signallers to be positioned in "significant and dangerous places."

He added: "But in this case, there was none. Notably, article 3 of the law stipulates that it is the mayor who must determine the number of signallers in cycling races . As it is a road incident involving a vulnerable [road] user, prosecution could happen, but the case looks complicated, given its specific context. "