Longtime Houston megachurch pastor Kirbyjon Caldwell will spend six years in federal prison for fraud.

Caldwell, the former spiritual counsel to two U.S. presidents, defrauded more than two dozen people of millions of dollars through the sale of worthless China bonds.

Caldwell and another defendant, Shreveport-based investment advisor Gregory Smith, encouraged almost 30 people to buy around $3.5 million China bonds between April 2013 and August 2014. Smith pleaded guilty last summer.

The 67-year old Caldwell was the senior pastor of Windsor Village United Methodist Church in Houston. He has been a spiritual adviser to U.S. Presidents George W. Bush and Barack Obama.

The church started with about 25 members in the 1980s but now has more than 16,000 - making it one of the biggest protestant congregations in the U.S.

Caldwell, a degree-holder from the Wharton School of Business, was found guilty of wire fraud and money laundering. He pleaded guilty in March to conspiracy to commit wire fraud.

Smith and Caldwell used their status to persuade several people they could earn returns as high as 15 times their original stake, court documents show.

The U.S. Securities and Exchange Commission considers the bonds as "memorabilia" - but they are  no longer recognized by the current China government and have no value, court records show.

"The defendants in this case abused the trust that the victims had placed in them," Acting U.S. Attorney Alexander Van Hook said.

It may be a year until Caldwell, who has prostate cancer, starts serving his sentence because of the risks posed to his health by the coronavirus.