Agriculture Minister Phil Gawne believes people ignoring current Foot and Mouth restrictions could have serious consequences for forthcoming sporting events.
On Monday, there were several reports of walkers using closed footpaths, notices being removed and signs being ripped up.
He says any decision about the Manx Grand Prix and Manx Two Day Trials going ahead will be dependent on being able to guarantee biosecurity:-
Commonwealth Games athletics squad in positive mood ahead of Glasgow
Five competitors - including three debutants - set to be involved
FC Isle of Man get pre-season underway with summer festival
Ravens get first runout ahead of new season
Swimming: Oscar Maddrell becomes triple British champion
Manx swimmer also breaks Island records during successful trip
Football: Mixed results for IoM Women in summer series
They welcomed Ynys Mon to The Bowl last weekend