Ro Khanna’s campaign manager resigned after U.S. Rep. Mike Honda filed a lawsuit alleging that his challenger’s aide stole sensitive fundraising information that was used to contact Honda’s donors.

The lawsuit, filed Thursday in federal court in San Jose, says Brian Parvizshahi obtained access to Honda’s donor list and other records in 2012, when he was an intern for a consultant that worked for Honda. It alleges that Parvizshahi accessed the Dropbox files 44 times after joining the Khanna campaign until Honda’s campaign discovered the breach in May.

Khanna, a former deputy assistant commerce secretary under President Barack Obama, said Friday that Parvizshahi left to avoid becoming a distraction and to focus on fighting the lawsuit. Khanna denied ever having access to Honda’s campaign information and said he believed Honda sued to divert attention from questions about his ethics in the highly competitive race.

Both candidates seeking to represent California’s 17th congressional district in the Silicon Valley area are Democrats. Honda is under scrutiny by the House Ethics Committee over allegations that his congressional aides performed campaign work.

“The timing of this lawsuit is extraordinarily suspicious,” Khanna said in a phone interview. “One wonders why he would sit on something until six weeks before an election.”

Parvizshahi didn’t immediately respond to a message left with Khanna. Court documents do not list an attorney for him.

“He’s a 25 year-old young man who now, unfortunately because of Mike Honda, has to go out and get his own lawyer to defend himself against a baseless lawsuit,” Khanna said.

Vedant Patel, a spokesman for Honda, said in a statement that it took time to assess “the depth and scope of the Khanna campaign’s cyber theft.”

“The charges are ones not to be taken lightly,” he said.

The lawsuit alleging fraud and theft, which also names Khanna, says the challenger began sending emails to Honda donors in October that raised the House ethics probe and asked to discuss the campaign. It says 16 recipients alerted the Honda campaign and that they were “likely the tip of the iceberg.”

Kyle Kondik, who tracks congressional races at the University of Virginia Center for Politics, said Honda is considered one of the most endangered House incumbents in the country but that it was unclear how the latest developments might affect the race.

Khanna, who lost to Honda in 2014, beat the eight-term incumbent by 2 percentage points in the June primary. In California primaries, the top two vote-getters advance regardless of political party.