The House Ethics Committee has launched an investigation of conflict of interest allegations against Rep. Shelley Berkley, D-Nev.

The launch of the probe throws a wrench into Berkley's campaign to unseat Sen. Dean Heller, a Republican. The race is widely viewed as one that could help determine which party controls the Senate.

Berkley is alleged to have improperly pushed for higher Medicare reimbursement rates for a kidney transplant program at a Las Vegas hospital where her husband, a nephrologist, works.

Berkley's Senate campaign said it welcomed a move that would increase transparency into the issue.

"We are pleased with the committee's decision to conduct a full and fair investigation, which will ensure all the facts are reviewed. We are confident that ultimately it will be clear that Congresswoman Berkley's one and only concern was for the health and well being of Nevada's patients," campaign manager Jessica Mackler said in a written statement.