An Oak Bluffs man was arrested Tuesday and will be charged with trafficking in fentanyl, a synthetic opioid that is responsible for a recent spike in overdoses, according to local law enforcement.

Arrested was John Hathaway Jr., 48, of Oak Bluffs, police said, after a raid at 4 p.m. Tuesday at 466A County Road in Oak Bluffs. Police said they seized 54 grams of fentanyl, and confiscated $4,756 in cash Mr. Hathaway was carrying at the time.

Edgartown police Lieut. Christopher Dolby, a member of the Martha's Vineyard Drug Task Force, said police will not know for sure the composition of the drugs seized, or whether it was mixed with another drug, until it is analyzed by an evidence lab. But police said they have enough evidence to charge Mr. Hathaway with trafficking in fentanyl.

Police said the arrest caps a lengthy investigation into heroin and fentanyl distribution on Martha’s Vineyard.

"We've been coming across it more and more often, like every other place," said Lieutenant Dolby.

Fentanyl, often mixed with heroin, can can cause “addiction, respiratory depression and arrest, unconsciousness, coma, and death. The high potency of fentanyl greatly increases risk of overdose, especially if a person who uses drugs is unaware that a powder or pill contains fentanyl,” according to the National Institute on Drug Abuse.

Mr. Hathaway was released after posting $2,000 bail after his arrest Tuesday. After he was arraigned Thursday in Edgartown district court on a charge of trafficking a class B substance (fentanyl), the Hon. J. Thomas Kirkman imposed revised bail of $25,000, and ordered Mr. Hathaway taken into custody again. He is due back in court for a probable cause hearing on April 28.

Also to be charged in connection with Tuesday's raid is Thomas Wilkins, 22. Police said he will be charged with illegal possession of the prescription narcotics Percocet and Suboxone.