Bud Light sales declines are accelerating, and shares of parent company Anheuser-Busch InBev (BUD) are falling alongside them.

New data from Nielsen revealed Bud Light sales declined 24.3% year-over-year in the week ending May 20 while Budweiser sales were down 20.4% during the same period. Last week sales were down 21.6% and 17.6% respectively. Driven by backlash from an advertising campaign with transgender influencer Dylan Mulvaney, Bud Light sales have now declined for six weeks, per Nielsen.

Shares of AbInBev fell nearly 5% on Tuesday, the worst intraday action on the stock since Mulvaney's post on April 1. Since the day of the post, ABInBev shares have fallen roughly 18%.

Citi analyst Simon Hales argues the drop in Budweiser sales could provide a buying opportunity for investors.

"There continues to be contagion to the wider ABInBev brand portfolio, with Budweiser, Busch and Michelob all weak again," Hales wrote in a note on Tuesday. "Meanwhile, Coors Light continue to see share gains accelerate. The latest data shows little sign that consumers are moving on from the Bud Light controversy, and we expect these issues will continue to weigh on investor sentiment. Nevertheless, we believe the pullback creates an interesting entry point for longer-term investors."

Citi expects the declining Bud Light sales to "continue to dominate news flow and weigh on short-term investor sentiment." But the firm believes AbInBev shares are oversold when considering the current declines in the context of AbInBev's overall business.

AbInBev echoed as much in early May when the company issued full-year EBITDA guidance in line with previously stated business goals.

On a call with investors following the release on May 4, AbInBev CEO Michel Dimitrios Doukeris didn't sound any alarms about the controversy's impact.

"With respect to the current situation and the impact of Bud Light sales, it is too early to have a full view," Doukeris said. "The Bud Light volume decline in the US over the first 3 weeks of April, as publicly reported, would represent around 1% of our overall global volumes for that period."