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.
Society appeals for help about traditional gypsy caravans on the Island
Do you know of any traditional gypsy caravans on the Island?
Government issues bird flu warning after infected buzzard found
The government's warning people not to touch sick or dead birds after a wild buzzard which died of bird flu was found in a garden near Bride.
Will new UK law be brought in to protect Manx renters from mould?
What consideration is the government giving to bringing in a UK law which protects renters from damp and mould?
Local Economy Forum launched to propose alternative to 'destructive' min wage increase
A Local Economy Forum is being launched to highlight what it's calling the destructive impact of the planned minimum wage increase.
Group raising money towards legal costs for new Summerland inquest
A campaign group is raising funds for a new inquest into the tragic Summerland fire of 1973.
Police appeal after Manx stone wall damaged
Police in the north of the Island are appealing for information after a car hit a stone wall.
MHK wants to see all private healthcare reports
An MHK has asked the Health and Social Care Minister to publish reports on the hospital’s private patient wing and services.
Let’s make Hop Tu Naa a boo-tiful night for all, say police
Police are reminding parents to know what their children are up to this Hop Tu Naa.
