A New Jersey state trooper has been unexpectedly reunited with the retired police officer who delivered him as a baby 27 years ago — by pulling him over.

Trooper Michael Patterson had stopped the motorist, Matthew Bailly, for a minor motor vehicle violation.

In conversation, Mr Bailly said he was a retired officer from the Piscataway Police Department, New Jersey State Police said.

Mr Patterson then told Mr Bailly that he was from the same town, prompting Mr Bailly to ask him where he used to live.

When Mr Patterson told him he had grown up on Poe Place, Mr Bailly said he remembered the street because he helped deliver a baby there 27 years ago.

Mr Bailly then described in great detail the colour and style of the house and told Mr Patterson the baby's name — Michael.

Mr Patterson then replied, "My name is Michael Patterson, sir. Thank you for delivering me."

Mr Patterson and his mother visited Mr Bailly and his wife at their home. ( Facebook: New Jersey State Police )

On October 5 1991, Mr Patterson's mother, Karen, was out shopping when she went into labour. After she had struggled home, her husband phoned a doctor.

Mr Bailly, who had been on the job for four years, was the first to respond to the incident.

Both the Patterson family and the Bailly family were "ecstatic" about the fateful reunion, and Mr Patterson and his mother visited Mr Bailly at his home, police said.

"We're not sure what the odds are of this happening — maybe they're close to the odds of a hole-in-one, winning the lottery, or being struck by lightning — but it happened," New Jersey State Police wrote on Facebook.

Mr Bailly and Mr Patterson took more photos together to mark the occasion and shared the photos with the state police.

A Facebook post about the chance meeting has amassed almost 9,000 shares but the main question on people's minds was — did Mr Patterson issue Mr Bailly a ticket?

The state police told the BBC Mr Bailly was stopped because of his vehicle's tinted windows and was let off with a warning.