Washington (CNN) Hillary Clinton is facing new criticism of her family's wealth and financial entanglements a week after she released financial records that omitted a company Bill Clinton has used as a conduit for his consulting work.

The former president was personally involved in setting up WJC, LLC, according to state filings obtained by CNN. (WJC are the initials for William Jefferson Clinton). It appears to exist in order to offer Clinton the tax and legal benefits of a limited liability company -- a standard business structure -- even though it had no employees or assets and only functioned as a pass-through for payments for his work.

Hillary Clinton didn't list it in her personal financial disclosure this month, and the company's existence was first reported by The Associated Press on Tuesday and confirmed in documents obtained by CNN.

"President Clinton set up a commonly used mechanism to manage his personal business affairs. All of the income has been reported and is accounted for. Anyone trying to paint this as anything more than that is playing politics," said Angel Urena, Bill Clinton's spokesman, when asked why WJC, LLC was set up.

It doesn't appear the Democratic presidential frontrunner violated any ethics rules: The company's non-existent assets are under the $1,000 reporting threshold, and Clinton listed the businesses that hired and paid her husband.

Campaign finance law experts said at first blush, they didn't see much to worry about.

"I don't remember seeing this, but it sounds like a tempest in a teapot because all of the activity was disclosed," said Kenneth Gross, the head of the political law practice for the firm Skadden Arps.

He said revealing the businesses that actually hired Clinton, rather than concealing the sources by saying his pay actually came from WJC, LLC, suggests the Clintons weren't attempting to hide the sources of their income.

"If this was used as a mechanism to evade disclosure, that would be a different story," Gross said.

But that didn't stop her 2016 opponents from pouncing.

Republican National Committee Chairman Reince Priebus insisted that Clinton "come forward immediately" to offer details on the company's activities and her knowledge of it.

"The revelation that the Clintons had a secret shell company that went unreported on Hillary Clinton's financial disclosures further demonstrates they are not giving voters the full picture of their wealth," Priebus said. "Clearly, there's a lot that they don't want voters to see."

The criticism of the Clintons' assets are part of a broader criticism against the couple. Opponents have highlighted their close relationships with long-time associates whose business interests aren't always apparent, their high-dollar paid speeches and their family foundation as troubling, asserting that the couple's secrecy is problematic.

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Bernie Sanders said Bill and Hillary Clinton "hustle money" by giving paid speeches, leaving the pair isolated from the world's realities because they've obtained "that type of wealth."

"When you hustle money like that, you don't sit in restaurants like this," the Vermont senator who's kicking off his 2016 bid for the Democratic presidential nomination told CNBC on Tuesday morning.

The company was set up first in Delaware in December 2008 and renewed there in June 2013, according to the state documents. It was also registered in New York in October 2009. Bill Clinton's signature was on the 2013 renewal as an "authorizing person."

In 2011, Clinton's WJC, LLC surfaced in a filing by his counselor, Doug Band, asking the State Department to approve his strategy firm's plans to hire the former president for "consulting services provided by President Clinton through WJC, LLC."

Band had also previously asked the State Department to sign off on three other companies' efforts to hire Clinton as a consultant and strategist.

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The company hasn't appeared at all in Hillary Clinton's personal financial disclosures, starting in 2008.

But that's not illegal: Federal disclosure laws require Clinton to list any sources of income for her husband worth more than $1,000. She has listed the companies that paid him -- while omitting a pass-through like WJC, LLC.

Though Clinton isn't being accused of breaking laws, the report has led to new scrutiny of the personal finances of a family that has at times -- such as when the former secretary of state asserted a year ago that she and Bill Clinton were "dead broke" when the left the White House, ignoring the family's massive earning potential -- been tone deaf to criticism of its wealth.

In 2012, Republican nominee Mitt Romney's time at the helm of investment firm Bain Capital and his off-key comments about his own wealth, such as offering to make a $10,000 bet in the middle of a GOP primary debate, harmed voters' perceptions of his ability to understand middle-class problems.

The Clinton family's wealth, including more than $30 million made through paid speeches since the beginning of 2014, and the family charitable foundation's acceptance of foreign donations while Hillary Clinton served as secretary of state, have led to assertions in 2016 that Clinton's complex personal finances obtained through temporary gigs have left her out of touch, as well.