KITTERY – A one-car crash killed a Dover, N.H., man after he eluded a New Hampshire liquor enforcement officer who spotted him speeding through downtown Portsmouth, N.H., and tried to stop him, police said Sunday.

Justin Harding, 22, was speeding through the winding streets of downtown Kittery shortly before 2 a.m. Saturday when his Mercedes Benz jumped the curb approaching the turn into Wallingford Square, struck a light pole and a tree, and crashed into a real estate office.

Investigators later learned that Harding was employed by a Mercedes dealership in Greenland, N.H., but was not authorized to be driving its vehicle. He was also driving with a suspended license, police said.

High speed and alcohol were blamed for the crash, which followed the attempt by the liquor enforcement officer to stop Harding’s vehicle in Portsmouth.

As the car continued to speed across the Memorial Bridge into Kittery, the officer turned off his lights and siren, discontinuing the pursuit while heading in the same direction.

Police said Harding, who was not wearing a seat belt, died of head injuries.