Amidst growing unrest in Montreal, organisers of next weekend's Canadian Grand Prix have cancelled Thursday's 'open day'.

Fans arriving at the circuit on Thursday were to have been given free access to the track including a pitlane walkabout however, in a statement issued on Sunday, Francois Dumontier, President of the Canadian Grand Prix, revealed that, reluctantly, the event has been cancelled, admitting that direct threats had been received.

"Following a serious examination of the situation, made necessary by public disruption threats and the difficulty to measure their precise validity, the organisers came to the conclusion that it is necessary to restrain the access to Circuit Gilles-Villeneuve and precisely the F1 pit lane, on the day preceding the first sessions on track," it read.

"When we finally made the decision, we weren't exactly happy, being fully aware that this activity is an important part of the appeal and the tradition of true friendliness at our event", added Dumontier. "Considering the various disruption threats made public recently, the free admission and the naturally openness character of the 'Open Doors' day, revealed some risks that we could not neglect.

"Under these circumstances, cancelling the 'Open Doors' day was the only action we could take. Unfortunately, for the fans and our spectators, it was impossible to escape from such responsibility."

The decision comes as student group CLASSE suggests that the race could be used as a platform for the ongoing demonstrations over tuition fees.

Dumontier also admitted that ticket sales for the Grand Prix are down this year as a direct result of the unrest. "Our ticket sales are down over the last month or so," he said. "People didn't buy the tickets, saying that they were afraid to come to Montreal."

At the heart of the unrest is the fact that students are unhappy at a planned hike to their tuition fees. However, the ill feeling has now expanded into wider social issues.

In a further blow to the event, the 'internet activist group' Anonymous has hacked a website selling tickets for the Grand Prix subsequently sending emails to fans who have bought tickets telling them not to attend. Details of more than 100 fans had their details leaked online, including their names, phone numbers, email addresses and even the prices they paid for their tickets.

Andres Hurtado of Calgary, who had spent $500 on tickets told CBC News: "It's very upsetting that they want to disrupt something like this, kind of an international event, to show whatever their purpose is,"

"I agree that they can freely protest," he added, "but when it comes down to something like this... I don't even live in Montreal and I'm getting attacked by this!"

The contents of the email to Frank Thoeringer of Ontario reveals why many fans might simply opt to avoid next weekend's event.

"Do not fool yourself into thinking that you can avoid or contain us, or that the police will protect you from our makeshift weapons," it reads. "There is nowhere to hide. We know every street, every alley, every park. We know where you will sleep, where you will shop and where you will drink. We have been planning to crash your party for some time now."

Undaunted, Thoeringer will still be going to the race. "I am coming to Montreal," he told CBC News. "I enjoy Formula One!