By Jim Melwert

NORRISTOWN, Pa. (CBS) — Officials in Montgomery County say hundreds of thousands of dollars of high-quality heroin is off the streets after a bust in Norristown.

County detectives intercepted a conversation on Monday, in which, according to investigators, a man was contacting a drug trafficker in Mexico about buying kilogram quantities of heroin.

He was connected to two people in the Philadelphia area and, after surveillance, authorities found a kilogram of heroin, $10,000 cash, and a handgun in  a home in Norristown.

Montgomery County district attorney Risa Ferman says the heroin has a street value of more than $300,000.

“But what really is so significant is just this amount that’s here in front of me has 33,000 doses,” she said today.  “That is a lot of heroin. It has the impact to do an enormous amount of destruction.”

Two Norristown residents, Galdiz Basurto-Leal and Erik Lopez, are being held, each in lieu of  $500,000 bail.  Investigators believe the heroin would have been cut and sold to other dealers in the area.