Rep. John Delaney (D-Md.) speaks at a Washington Post Live event on Innovation Through Collaboration, the role of public-private partnership, in February 2015. (Kate Patterson/for The Washington Post)

Rep. John Delaney (D-Md.) charges in a Federal Election Commission complaint that his Republican challenger in Western Maryland’s 6th District is illegally coordinating with a super PAC, funded almost exclusively by her husband, that has spent more than $1 million on her campaign.

The complaint, filed Wednesday, accuses GOP candidate Amie Hoeber and her husband, former Qualcomm executive Mark Epstein, of sharing video footage, a polling firm and a telephone outreach company, which Delaney says are “flagrant violations” of rules barring a candidate’s campaign committee and a super PAC from acting in concert.

Although federal law limits donations to candidate committees — except from the candidates themselves — super PACs can accept unlimited amounts from individuals and corporations.

Since mid-2015, Maryland USA has spent $1.3 million on Hoeber’s primary and general election campaigns. Records show that her campaign committee, Amie Hoeber for Congress, is the sole campaign supported by Maryland USA’s funds. With the exception of $1,000 from another individual, Epstein is the only contributor to Maryland USA, which has $2.1 million in donations.

Gov. Larry Hogan endorses Amie Hoeber in her bid to unseat Rep. John Delaney at the Rosborough Cultural Arts Building Theater at Asbury Methodist Village in Gaithersburg, Md., on Sept. 14. (Marvin Joseph/The Washington Post)

“Maryland USA has no genuine existence apart from Amie Hoeber,” Delaney’s complaint said.

Hoeber called Delaney’s claims “fraudulent” and said her campaign’s activities have been vetted by legal counsel. Epstein said that although he gives money to Maryland USA, he has no say over how it is used. “When I send the money, it goes over the transom,” he said. “That’s the last I see of it.”

The FEC often takes months after a complaint is filed to decide whether to open an investigation. But filing a complaint can still put an opponent on the defensive and provide grist for ads.

While the complaint alleges that Delaney and his campaign “face a significant competitive harm” because of the alleged coordination, Delaney has significant resources of his own.

Surveys place him among the wealthiest members of Congress, with an estimated net worth of $90 million to $150 million. The former financial services entrepreneur spent $2.3 million of his own money in 2012 to unseat Republican incumbent Roscoe G. Bartlett and $1 million to ward off a strong challenge from Dan Bongino in 2014.

He’s raised about $1 million so far for this campaign, according to the most recent finance reports. Hoeber, a defense consultant and Reagan-era deputy undersecretary of the Army, has put $562,000 into her campaign, representing the bulk of the $769,000 she’s raised, according to FEC reports. The candidates live within several doors of each other in Potomac’s Bradley Hills neighborhood.

The law is intended to establish a firewall, but many super PACs are set up and financed by individuals with close ties to the candidates they support.

Maryland USA has been openly operating as a single-candidate super PAC for more than a year. Delaney spokesman Will McDonald said that the campaign waited to file a complaint until Maryland USA spent advertising dollars directly against Delaney. The PAC launched its first general-election ads on cable television this week.

The FEC complaint follows a Huffington Post article by Hoeber this month in which she called one of Delaney’s former companies, CapitalSource, “a payday lending company” that handed out “predatory loans — some with interest rates as high as 18% — and then foreclosing on debtor’s homes the moment they defaulted.”

CapitalSource, founded by Delaney in 2000, lent $30 million in 2009 to Aeon Financial, a firm that bought liens placed on nearly 2,000 homes in the District and Maryland when owners fell behind on their taxes, then charged thousands in fees to avoid foreclosure. Aeon’s activities were the subject of a 2013 Washington Post story.

Delaney spokesman Will McDonald said at the time that CapitalSource made more than 5,000 loans totaling an estimated $20 billion under Delaney’s tenure as chief executive, and that he was not aware of issues involving Aeon. Delaney left CapitalSource after being elected to Congress.

He said in an email Thursday that calling CapitalSource a payday lender “is so far from the truth it would be laughable if Hoeber weren’t running for federal office and knowingly lying to the public for her own political gain.”

The complaint cites FEC filings that show links between Hoeber and Maryland USA as evidence of improper coordination. Epstein is listed as “treasurer and custodian of records” in the July 2015 FEC filing that created Hoeber’s campaign committee. His name was removed in an amended filing in October, just before his initial $300,000 contribution to the PAC.

The document describes footage from Hoeber’s 2015 online video announcing her candidacy that appears in two subsequent online spots produced by Maryland USA. The Hoeber campaign and Maryland USA also hired the same public opinion research firm, Wilson Perkins Allen of Oklahoma City. The super PAC paid $28,300 to the company in November and December of 2015; the campaign paid $25,200 in 2016.

The complaint also cites FEC filings showing that the Hoeber campaign and Maryland USA used the same Baltimore firm, 1360 LLC, earlier this year. The super PAC paid $2,500 for “database services” while Hoeber’s campaign paid $2,144 for “voter telephone contact.”