The National Bureau of Statistics (NBS) declined to comment on how churches fit into their GDP figures, but a source there said they were included as “non-profit”, which falls under “other services” in the latest figures. In 2013, the category contributed 2.5 percent of GDP, the same as the financial sector.

A former banker at Nigeria’s United Bank for Africa , who declined to be named, recalled being approached five years ago by a church that was bringing in $5 million a week from contributions at home or abroad.

“They wanted to make some pretty big investments: real estate, shares,” he said. “They wanted to issue a bond to borrow, and then use the weekly flows to pay the coupon.”

In the end, he said, the bank turned down the proposal on ethical grounds.

TB Joshua: smiles to the bank. Forbes says he is worth $15million

Yet Nigerian churches do often invest large amounts of their congregations’ money in shares and property, at home and abroad, he and another banking source said.

One pastor bought 3 billion naira ($18 million) worth of shares in the defunct Finbank, which later merged with FCMB , after it was rescued in a bail-out in 2009, a fund manager who handled the deal told Reuters. The pastor used a nominee trust account to keep his name off the books.

In 2011, Oyakhilome was investigated by the Economic and Financial Crimes Commission (EFCC) and charged with laundering $35 million of contributions to his church in foreign bank accounts. He denied all wrongdoing and the case was dismissed for lack of evidence.

Oyakhilome was not available for comment and Joshua’s media team declined a request for an interview with him.

MIDAS TOUCH

Oyedepo’s headquarters, “Canaanland”, is a 10,500-acre (4250-hectare) campus in Ota, outside the commercial capital Lagos. It comprises a university, two halls of accommodation, restaurants and a church seating 50,000 people, with a total overflow capacity of five times that.

“You can see that everything this man touches turns to gold,” Nigerian Agriculture Minister Akinwumi Adesina said in a speech at a reception for Oyedepo’s 60th birthday at Canaanland last month.

“May the grace of God abide with you,” he added, to a rapturous “Amen!” from the guests in a marquee.