Seven years ago, Lakewood Church, the Houston megachurch led by Joel Osteen, the prominent televangelist, reported that $200,000 in cash and $400,000 in checks had been stolen from a church safe.

Last month, the money may have been discovered — not by detectives or church personnel, but rather by a plumber fixing a toilet inside a church bathroom.

The plumber revealed the discovery on Thursday when he called into a Houston radio show.

“There was a loose toilet in the wall, and we removed the tile,” he said on 100.3 FM’s morning show. “We went to go remove the toilet, and I moved some insulation away and about 500 envelopes fell out of the wall.”

His reaction? “Oh, wow.”

The plumber said he contacted a maintenance supervisor and then gave the church the envelopes. On Friday, the Houston police confirmed that the money appeared to be connected to the 2014 theft.

In a statement on Twitter, the department said that officers responded to a report of property discovered at the church on Nov. 10 and were told by church members that a “large amount of money, including cash, checks and money orders” had been found inside a wall during a renovation project.

Burglary and theft investigators responded and an undisclosed amount of money was inventoried, documented and left in the custody of the church since it had been found on Lakewood’s property, the police said.

“Evidence from the recovered checks suggests this November case is connected to a March 9, 2014 theft report of undisclosed amounts of money at the church,” the police said, adding that the investigation was continuing.

In a statement, Lakewood Church confirmed the discovery.

“Recently, while repair work was being done at Lakewood Church, an undisclosed amount of cash and checks were found,” the church said. “Lakewood immediately notified the Houston Police Department and is assisting them with their investigation. Lakewood has no further comment at this time.”

Mr. Osteen is among the country’s best-known televangelists, and his church, which holds services in the former Compaq Center, once home to the Houston Rockets, seats about 16,000 people. Before the pandemic, the church had been drawing an average of about 42,000 people to services every week, according to a church spokesman.

The 2014 theft from the church’s safe was discovered by a church employee, a Houston police spokesman told The Houston Chronicle that year.

Lakewood Church said in a statement at the time that the “funds were fully insured, and we are working with our insurance company to restore the stolen funds to the church,” the newspaper reported. The church and Crime Stoppers of Houston had offered $25,000 for information that led to the arrest of those responsible for the theft, according to The Chronicle.

The plumber, who identified himself only as Justin, revealed that he had found the money when he called “The Morning Bullpen with George Mo and Erik” on Thursday.

The hosts had asked callers to share stories of the valuable things they had found and had fielded calls about a lost wedding ring and a $100 bill when they heard from the plumber, according to George Lindsey, a host of the show.

“It was the most unique and incredible phone call I have had in my 25-plus year radio career — without a doubt,” Mr. Lindsey said in an interview on Friday. He said the show went to a commercial break to confirm that the caller wasn’t pulling a prank and then let the plumber tell his story on air.

“I wish we had video of all of our faces as he was telling the story because it was like: Are you kidding me?” Mr. Lindsey said, adding that the 2014 theft was “big news” in Houston.

During the call, the plumber noted that there was a $25,000 reward offered, saying with a laugh, “I need some compensation.” He said he never thought about pocketing any of the envelopes.

“I’m an honest man,” he said.

Rania Mankarious, chief executive of Crime Stoppers of Houston, said $20,000 of the reward had been offered by Lakewood Church, which donated the money to Crime Stoppers after a year passed with no breaks in the case.

The organization still has a $5,000 reward for the case, she said, but the money would be given only for information that helped investigators identify, charge or arrest a suspect.

Someone who found the money would not qualify for the reward, unless the discovery led the police to a suspect, she said.

Mr. Lindsey said he believed that the plumber was frustrated that he hadn’t heard anything from the church or the police since he found the stash on Nov. 10.

“Nobody said thank you,” Mr. Lindsey said. “Nobody has said a word to this guy. He has solved a case that has been on the books for seven years.”