Mar.31, 2010, 11:51 pm US/Eastern

ABINGTON, Pa. (CBS 3) ―The FBI, along with county investigators, dug up the yard of a Montgomery County mansion Wednesday as part of an alleged money laundering investigation.

Investigators were looking for cash in the yard of an Abington home in the 1600 block of Stocton Road.

Eyewitnesses in the neighborhood of million dollar homes say they saw the FBI uncover what appeared to be bags of cash.

According to sources, the search is part of a money laundering operation tied to organized crime.

Sources also told Eyewitness News that the home belongs to Joe Mastranardo, who is the son-in-law of the late Philadelphia Mayor Frank Rizzo.

"It's a pretty quiet neighborhood and nothing too much goes on and then of course something like this comes as a big surprise," neighbor Richard Wiener said.

Mastranardo is currently in the Montgomery County Correctional Facility for violating probation. He was convicted of bookmaking in 2006.

The investigation is ongoing.