Sandra Kuba, a former senior financial analyst for Disney’s revenue operations unit, says she has filed a series of whistleblower tips with the U.S. Securities and Exchange Commission, alleging that the entertainment conglomerate repeatedly and systematically overstated its revenue for years, according to a MarketWatch report, by as much as $6 billion in a single year. But Disney has pushed back on the claim.

A Walt Disney spokesperson said that “This former employee, who was fired for cause, has persistently made patently false claims for over two years. The claims she made to the company were thoroughly investigated and found to be utterly baseless. It is unfortunate that MarketWatch, which has been aware of the facts for months, knowingly and deliberately chose to give Ms. Kuba’s unfounded claims a platform.”

The Dow Jones-owned business news outlet, which reviewed the filings, said the allegations involved the parks and resort segment, and included fictitious revenue records for complimentary golf rounds or free guest promotions, for example. In another instance, Kuba accused theme park employees of sometimes recording gift card revenue twice or recording gift card revenue at face value even if park guests paid a discounted price.

Kuba said she first made the complaints to the SEC in August 2017 and was reportedly fired from her position at Disney a month later, after working at the company for 18 years. She also filed a whistleblower-retaliation complaint with the Labor Department’s Occupational Safety and Health Administration, said MarketWatch.

Shares of Disney began paring gains for the day after the report was published, slightly after 3 p.m. Eastern. The stock ended up slightly Monday, less than 0.1%, but has since slid into negative territory in after-hours trading, down as much as 0.4%. The broader market finished the trading session in the green, with the S&P 500 up 1.2%, the NASDAQ up 1.4% and the Dow Jones Industrial Average up nearly 1%.

The SEC declined to comment.

MarketWatch also noted that Kuba had withdrawn her claim challenging her termination from her job.