Napier has had an influx of synthetic cannabis buyers after both shops that sold the drugs in Hastings were closed by the Health Ministry.
Hawke's Bay police had increased their focus on the drug due to the influx, they said.
The two shops selling synthetic cannabis in Hastings closed this week due to breaching bylaws.
That has led to many Hastings users travelling to Napier to buy the drug from Adult Selections in Dickens St.
Police issued a statement today saying they had "used the opportunity to carry out vehicle stops on Dickens St checking for driver-licence breaches, registration and warrants of fitness, people wanted on warrants and people with outstanding fines".
In just two hours yesterday morning they issued more than 40 tickets outside the shop. They also arrested a man who owed more than $40,000 in unpaid fines.
Sergeant Nigel Hurley said synthetic cannabis had a high criminal customer base and the influx of people into Napier this week provided police with a good opportunity to check vehicles and people.
"The neighbouring businesses of these synthetic cannabis retailers have had enough of the undesirable element hanging around on the street and in the area,'' Hurley said.
"Police support them [the businesses] and we have been targeting members of the criminal fraternity who make up a large portion of the synthetic cannabis market.
"We will continue to focus on these people in a bid to reduce criminal offending across the board."
Meanwhile, a 49-year-old Hastings woman is due to appear in the Hastings District Court this week on charges of selling synthetic cannabis without a licence.
The woman was arrested yesterday after she allegedly sold the drug from her Hastings house.
Police found a large amount of the drug and cash at her home. The penalties for selling synthetic cannabis without a licence are three months' jail and a $40,000 fine.
The ministry's Psychoactive Substances Regulatory Authority said it had suspended two interim retail licences in Hastings as it "holds concerns that these licences may not comply with the requirements of the local approved products policy (LAPP) adopted by the Hastings District Council (HDC) and now in effect".
Under the council's policy licensed psychoactive substance retailers are confined to certain parts of the CBD and cannot be situated within certain distances of churches or educational facilities. They must also be at least 300 metres away from another legal-high store.
Further regulatory action may include lifting the suspensions or taking action to cancel licences. The 21-day suspension period will end on March 28.
- Fairfax Media