The church attended by George H.W. Bush and Barbara Bush paid Jeb Bush $50,000 for a speech. Jeb, running for Florida governor, watched election results with his parents in Miami, Nov. 5, 2002. REUTERS/Carl Juste

After leaving the Florida governorship, Jeb Bush often commanded tens of thousands of dollars for speaking engagements. Some of his bigger checks were signed by major corporations, private universities with considerable endowments, overseas business conferences -- and a church in Houston frequented for more than 50 years by his parents, former U.S. President George H.W. Bush and former first lady Barbara Bush.

The former Florida governor charged one of his highest fees to St. Martin's Episcopal Church last year for a Sept. 30 event, according to a financial disclosure form with the Federal Election Commission. The fee of $50,000 was his fifth-highest rate in 2014 of 43 events stateside.

Those who received a better deal than Bush's family church included FedEx, which made more than $9 billion during the 2014 fiscal year and paid Bush $28,000 for his January speech, Vanderbilt University, which has a $4 billion endowment and wrote him a check for $45,000 in October, and electrical contractor Altec Industries, which paid Bush $25,000 -- half of the St. Martin's invoice.

Bush's usual rate seems to be $42,500, which the Distinguished Speaker Series of Southern California, Hanover Insurance Group and professional service giant KPMG all paid, among about a dozen others.

The Bush family has been affiliated with St. Martin's Episcopal since Jeb's parents moved to Houston in 1959, according to David L. Holmes' account in "The Faiths of the Founding Fathers." Jeb's sister Doro Bush Koch recounted her friends congratulating their father at the church on his 1966 congressional win in her autobiography,"My Father, My President: A Personal Account of the Life of George H.W. Bush."

Over the years, George H.W. and Barbara Bush taught Sunday school at the church, and the former president served as a vestryman. While Jeb Bush now attends a Catholic church in Coral Gables, Florida, his parents still remain active at St. Martin's; they attended the church as recently as Nov. 2014 for the church's annual veterans' service.

Speaking fees are typically based on factors such as time and preparation, but it is unclear what prompted the church's large bill. Jeb Bush has donated his speaking fees to charity in the past -- he did so for four events last year, but he did not itemize the church visit as such on the FEC forms.

Bush's team said that some of the speaking fee was given back to the church -- although the team would not specify how much.

"He donated a portion of those proceeds to the church," Bush spokeswoman Kristy Campbell told International Business Times. "St. Martin’s was one of the recipients of the $307,944 Gov. and Mrs. Bush contributed to charitable organizations in 2014, which is on top of the countless hours a year they donate to the various causes they support."

The nature of Jeb Bush's speech or event is also unclear. After multiple inquiries, his campaign confirmed that Bush gave an address at a stewardship dinner the church hosted for fundraising purposes. The campaign declined to disclose the subject matter addressed in the Sept. 30 speech.

No media reports link him to any appearances in the area at the time. He toured an Arkansas school that day to campaign for Republican gubernatorial candidate Asa Hutchinson.

St. Martin's does not appear to have advertised Bush's visit. Although the church frequently promotes its speaker series events, there is no mention of him or a Sept. 30 event on its website or Facebook page. The church has more than 8,400 congregants, but there seems to be no trace on social media of a Bush speech or appearance. (A search for Bush's name on Twitter in the dates from Sept. 30 to Oct. 4 doesn't surface any posts that indicate he was at the church in person or delivered a speech via Skype or video.)

St. Martin's declined to comment or to confirm Bush's visit, and referred IBT to the candidate's office. "It is our policy that we do not make any comments relating to anyone in the Bush family," a spokesperson wrote in an email.