Restrictions introduced after the foot-and-mouth outbreak in Surrey will remain in place until September, the county council has said.
Restriction zones and culling of herds followed the outbreak
Trading standards manager Peter Denard, who said barriers were still being ignored or torn down at 11 sites.
The virus could persist in the soil for "considerable time" and it was "vital" people stayed away, he added.
Restrictions would still be enforced where the disease was either found or strongly suspected last year, he said.
There are 11 sites in Egham, Englefield Green, Laleham, Normandy, Ottershaw, Ripley, Staines, Virginia Water, and Wood Street village, where either incursions have taken place or signs or barriers have been removed, he added.
"Nobody should be under the impression that all the county's foot-and-mouth restrictions have been lifted.
"There is a continuing problem with keep out signs and tapes being ripped down unofficially and that is why we are now advising that some restrictions will remain in place until September," he said.
Enforcement patrols were set to continue and anyone found breaching restrictions could be prosecuted and fined or jailed, he warned.
He added that a number of formal warnings have already been issued.
People have been urged to report any breaches of restrictions.
The first outbreak of the disease in August was traced to a laboratory at Pirbright.
The second outbreak in the county, happened a month later in Runnymede, about 11 miles (17km) away.