COLONIE — An Albany County jail inmate found dead Saturday is suspected to have been killed by a lethal form of heroin causing overdoses throughout the south, Sheriff Craig Apple said Sunday.

Apple released a statement Sunday concerning the death of Shane Lemperle, who the sheriff's office said was found unresponsive in his cell at 7:30 a.m. Saturday.

An exact cause of death has not been determined. An autopsy will not be done until Monday.

Apple said Lemperle was found with a dark gray powder hidden inside one of the socks he was wearing. A test of the powder revealed it to be a mix of heroin and fentanyl, what investigators suspect is a drug called "Grey Death."

"It's deadly," Sheriff Apple said. "We believed it was smuggled into the jail, probably passed through in a kiss."

The drug has been known to have lead to lethal overdoses in southern states, but had not been seen yet by the Albany County Sheriff's Office or Albany County coroner. The powder will be submitted to the State Police for more testing.

Apple said "Grey Death" is a combination of over-the-counter and prescription drugs with heroin, fentanyl and carfentinal, which is used to tranquilize large animals like elephants.

"It's really nasty," Apple said.

Lemperle's death remains under investigation. He was brought to the jail on Aug. 12 from the Watervliet City Court on a charge of conspiracy and criminal possession of stolen property and was currently being held for a parole violation.

In 2014, Lemperle was charged with endangering the welfare of a child, in addition to other charges, for allegedly bringing a 3-year-old with him while he burglarized Kneers Automotive in Brunswick. At the time he was released to Rensselaer County Probation pending the outcome of that case.

Lemperle's is the second death at the Albany County Jail since the summer.

In July, 36-year-old Cohoes resident Jessica Falco was found unresponsive in her cell by a correction officer during breakfast, also on a Saturday.

The officer sounded the emergency alarm for assistance and immediately began performing CPR. Medical staff and Colonie EMS responded and efforts to resuscitate Falco were unsuccessful, Apple said at the time.

Falco was incarcerated on March 7 and was serving a one-year sentence for probation violation.