WASHINGTON – Vice President Mike Pence is using a legal defense fund created by a former top gubernatorial aide to pay about $500,000 in legal fees from special counsel Robert Mueller's investigation, according to a White House official.

Pence disclosed the creation of the fund on his annual financial disclosure report that was released Thursday.

The report shows the fund was created in December by Jim Atterholt, who served as Pence's chief of staff when he was Indiana's governor.

Atterholt started the fund with $25. The rest of the donations have been collected since the start of the year and therefore won't have to be detailed until the 2019 report is filed. But Atterholt said he expects Pence's office to release donors' names after all the bills are paid, which could be in the next few weeks.

The defense fund is raising about $500,000, which about matches the estimated total legal costs, according to a White House official.

Pence hired an attorney, former U.S. Attorney Richard Cullen, after Mueller was appointed in 2017. But he was not billed until the end of Mueller's investigation into Russia's interference in the 2016 election.

Atterholt said he volunteered to start the fund because he doesn't believe legal bills should be the cost of public service.

"He is a very decent and honorable person," Atterholt said of Pence. "But he is not someone of great financial means."

In fact, Pence's disclosure report shows that, unlike his boss, he had no reportable income outside of his salary – which was $230,700 last year. His wife, Karen, earned between $2,501 and $5,000 in royalties for a children's book she illustrated.

The Pences' largest asset is a pension from the state of Indiana valued between $500,000 and $1 million.

They have a modest bank account and no longer have the credit card debt of between $15,001 and $50,000 that they reported last year. But they still owe between $100,001 and $250,000 in loans that were taken out to help pay for their children's educations.

Pence was not asked by Mueller's team for an interview but provided documents, a White House official previously said.

Pence had been on the periphery of the investigation. His exposure was primarily through statements he'd made that were later contradicted.

Pence had publicly announced on Jan. 15, 2017, that former national security adviser Michael Flynn assured him he had not discussed with Russian officials the sanctions that then-President Barack Obama had imposed on Russia before leaving office.

Flynn was fired after the White House was told by the Justice Department that Flynn had lied about those conversations.

Trump's pressure on former FBI director James Comey not to go after Flynn was one of the "key issues and events" that Mueller's team considered when investigating whether Trump tried to illegally thwart the investigation.

"They're not playing hop scotch," Atterholt said of Mueller's team. "These are very serious people and anyone who interacts with them would be wise to have legal counsel."

Donors to the defense fund have to certify that Pence himself had not requested the money and that the contribution comes from personal funds. Donors must also be U.S. citizens and cannot be a registered lobbyist, government employee, government contractor or agent of a foreign government.

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