The stretch of beach where the dog was killed is a designated Hastings District Council (HDC) dogs off leash zone, and bikes on the beach were supposed to go no faster than 20km/h.
While the Hastings District Council did not have a bylaw in place banning the use of motorbikes on Haumoana beach, there is one which designates speed limits in various areas of the district. For beaches, that is a maximum of 20km/h.
Council's community safety manager Phil Evans confirmed Mrs Hamilton was allowed to be walking Rosie unrestrained on that stretch of beach.
"The area of Haumoana-Te Awanga beach from the mouth of the Tukituki River south to the boundary of the Clifton No2 camp ... Haumoana, is designated as an off-lead area for dogs," he said.
A TV3 news feature which aired recently brought home the reality that quadbikes were not an isolated issue, with a lack of helmets, speeding and overloading also posing problems at Waimarama Beach.
Last year, HDC enforced a ban at the southern end of the popular tourist spot during summer, where there are red flags monitored by lifeguards, but it was not well policed, locals said.
A charge of dangerous driving carries a maximum penalty of $4500 fine, or three months' imprisonment.