(NEXSTAR) — A plumber in Houston claims to have found “about 500” envelopes full of cash and checks inside a wall at Joel Osteen’s Lakewood Church.

Investigators believe the find may have something to do with a 2014 theft at the megachurch, police confirmed.

The plumber made the claim Thursday morning during a call-in to a Houston radio show, saying he found the envelopes around a month back while working in a bathroom.

“I went to go remove the toilet and I moved some insulation away and about 500 envelopes fell out of the wall. I was like, ‘Oh wow,’” the plumber said on the Houston radio program, as first reported by Click2Houston.

The plumber also said he notified an employee at the church, who contacted the authorities.

“About 2:30 p.m. on November 10, Houston police officers were called to Lakewood Church at 3700 Southwest Freeway for a report of property discovered in the building,” the Houston Police Department confirmed Friday on Twitter. “Church members stated that during a renovation project, a large amount of money — including cash, checks and money orders — was found inside a wall.”

An “undisclosed amount” of money was found, police said, though it was left with the church. Authorities now believe the find is connected to a 2014 theft at the church, during which $600,000 in donations was stolen.

The investigation is ongoing.