A New York City correction officer surrendered to state police on Friday and was charged with supplying heroin for sale on the Shinnecock Indian reservation on eastern Long Island.

The arrest comes a day after police nabbed more than a dozen people in raids on the reservation and elsewhere, breaking up what they termed "a major narcotics distribution network."

Gary Morton, 25, was scheduled to be arraigned Saturday morning in Southampton Town Court, charged with second-degree conspiracy. The Jamaica, Queens, resident is the nephew of Michael Morton, who was arrested Thursday, charged with selling heroin on the reservation.

State police said they intended to arrest Morton at his job at Riker's Island on Thursday, but he never reported for duty. He surrendered at the state police barracks in Farmingdale shortly after noon Friday.

A spokesman for the Department of Correction confirmed Morton has worked at Riker's Island since November 2006.

Authorities were not certain if Morton had a lawyer. Morton's home phone number was unlisted.

State police on Thursday identified the leader of the cocaine ring as Awan Gumbs, 26, of Hampton Bays, the son of Shinnecock Nation Tribal Trustee Lance A. Gumbs. Police said some of the drug sales took place inside his father's business, the Shinnecock Outpost in Southampton.

Suffolk District Attorney Thomas Spota said his office began an investigation of drug sales on the reservation after receiving a letter in May 2006 from the Shinnecock trustees requesting help.

Lance Gumbs and other trustees confirmed in a statement that the tribe had "asked for the assistance of outside law enforcement agencies."

"We are a Tribe, as closely knit as an extended family, and the police action that took place with our consent on our lands, against some of our people, touches every household and causes pain to us all," the statement said.

Awan Gumbs' lawyer suggested late Thursday the charge against his client could be motivated by retribution for, among other things, the Shinnecocks' efforts to open a casino in the area.

"Is this politically driven by the fact that his father is someone who has lawsuits against the government?" Steven Politi asked.

Police also announced the arrests of 10 others on various charges ranging from conspiracy to marijuana possession and weapons charges. Police said they seized three luxury SUVs, another automobile, handguns, a loaded AK-47 assault weapon, rifles and shotguns during the arrests.

The Shinnecocks' 800-acre reservation in Southampton is peppered with modest single-family homes -- a stark contrast to the palatial Hamptons estates just up the road. For several years, the Shinnecocks have been trying to open a 65,000-square-foot casino in nearby Hampton Bays, but opposition from town and state officials has stymied their efforts.