KITTERY — Town officials who believe residents are registering their cars in New Hampshire to avoid sales and excise taxes in Maine are preparing to crack down on the practice.

Chuck Denault of the Kittery Police Department brought in more than $60,000 in unpaid excise taxes last year. This year he is working on 300 cases as a crackdown looms on May 1.

Maine law says anyone living in the state longer than 30 days has to pay a sales tax on the purchase of a new car, even if it was bought in another state. An excise tax must be paid every year after that to fund new roads and other local services.

But a case involving a dispute over a vehicle operated by a Mainer and leased by a New Hampshire-based company illustrates that the law is not always black and white on the matter.

Kittery resident Keith Zeller said his boss, Portsmouth, N.H., business owner Julie Vogt, decided to lease a company car for Zeller and his wife, who both work for Vogt at MoneyMatters in Kittery.

He said Maine taxation and motor vehicle officials insisted the Zellers register the new Subaru Outback in New Hampshire, since that’s where Vogt lives, owns her firm and does all her business.

But Kittery Police Chief Ed Strong insisted Friday that the others “aren’t reading the law right.” He said a new change to Maine law says the “owners” of the car are those who have “exclusive rights” to it.

So he stands behind Denault in saying the Zellers need to register the car in Maine. Now Zeller faces a possible $565-a-day illegal registration fine from Denault.