Footage is being circulated of an incident where a man crossed the closed MGP course, a matter of seconds before a bike speeds down it.
It happened at St Ninian's, with the man helped to safety through barriers by spectators on the other side of the course by the EVF garage.
Police issued a warning saying it could have ended "horrendously".
They've reminded people of the dangers and said police will work with marshals to prosecute anyone who breaks road closure restrictions.
Great Laxey Wheel upgrades to see old ticket office removed
An old ticket office in Laxey will be knocked down ahead of new work.
MHK to question plans for improving Island's mental health services
Will mental health services be improved on the Isle of Man?
Colby Glen path shut until next April
A popular footpath in the south of the Island will remain closed until next April.
If you Trick Or Treat, don't trouble the street!
If you're going trick or treating this Hop-tu-Naa, police are warning you not to get carried away.
German newspaper says hello from the Island - and Queen Victoria
A leading German newspaper is urging its readers to sample the delights of the Isle of Man.
Don't buy electric cars, says Manx salvage firm
A salvage company from the south of the Island has told people not to buy electric vehicles.
Aurora-watchers could be in for Friday treat!
Could the Isle of Man get a celestial lightshow to kick off the weekend?
Peel's pulsing UFO has people perplexed
Did you see the UFO off the Island's west coast last night?
