A major supplier of heroin to Southern New Hampshire is behind bars and five more drug dealers are expected to join him before the weekend is over, police said.

Kingston, Plaistow and Lawrence, Mass., police collaborated on the investigation of Luis Peguro-Tejada, 35, of Lawrence, who was arrested on numerous drug trafficking charges Wednesday. During a search of his 245 Andover St. apartment, police confiscated 327 grams of heroin worth an estimated $32,700, and $14,000 in cash.

Police also have warrants for five New Hampshire drug dealers, who they believe were buying from Peguro-Tejada and then selling to teenagers in Southern New Hampshire, according to Kingston police Chief Donald Briggs.

The other suspects regularly went to Lawrence to buy from Peguro-Tejada, but he also occasionally made trips to New Hampshire, Briggs said.

An undercover Kingston officer bought drugs from Peguro-Tejada in Lawrence four times in the last two weeks, police said. When Peguro-Tejada went to meet the officer for a fifth transaction, Lawrence police pulled him over and arrested him.

"We've been working with Plaistow and Lawrence to stop the drugs from infiltrating into New Hampshire," Briggs said. "So we are going to the source rather than let the source come to us."

The additional arrests are expected by tomorrow night, according to Plaistow Detective Patrick Caggiano. Once that's done, much of the heroin available in the area should be cut off, he said.

"This is a significant disruption, specifically to heroin users, in this area," Caggiano said.

Plaistow police said they identified Peguro-Tejada two months ago as the major source of heroin in the community. Kingston police concurred that he was a longtime supplier and the departments contacted Lawrence.

Lawrence police Chief John Romero said his department didn't have Peguro-Tejada on its radar before they heard from New Hampshire police. But, he said, Lawrence police soon found Peguro-Tejada was a major player in Massachusetts drug trafficking, as well.

Romero said there's "no question" a majority of drugs in Southern New Hampshire come from Massachusetts.

Once Peguro-Tejada was in custody, police searched his apartment. His girlfriend, Luicy Paguro-Marinez, 31, was at home and immediately arrested as well.

Plaistow canine Stryker found 223 bags of heroin in the bedroom, as well as scales, money stashed in empty food containers, plastic gloves and a number of false identifications, according to police paperwork. Lawrence police also are investigating a number of electronics in the apartment, which they believe were stolen, Romero said.

Peguro-Tejada was charged with four counts of trafficking a class A drug, four counts of trafficking class A drugs in a school zone and one count of providing a false name — Tyron Corujo. Paguro-Marinez was charged with trafficking a class A drug and providing a false name — Yaritza Baez.

He was held on $250,000 cash bail and she was held on $100,000 at their arraignments yesterday, Romero said. If convicted, they could face 15 years in prison.