(CNN) — Andrea Riseborough may not be a name that rings many bells for the average moviegoer.

But, chances are, your favorite actor in that one movie you love knows exactly who she is. And they want her to win an Oscar.

It’s, frankly, a strange tale — one that began in October with the limited release of a small-time independent film called “To Leslie,” about what happens when a single mother wins the lottery and runs out of money. Riseborough plays the titular Leslie, in a performance widely praised by critics as some of the best work of her career.

And just last week, Riseborough was nominated for a best actress Academy Award, her first Oscar nomination.

But there are questions surrounding her nomination, which came after a very public push by multiple big-time Hollywood stars — think Gwyneth Paltrow and Amy Adams. Now, without specifically mentioning Riseborough or “To Leslie,” the Academy of Motion Picture Arts and Sciences says it is investigating this year’s campaign procedures to ensure no rules were broken. (Contacting Academy members to promote a film or push for an award is forbidden.)

So dim the lights and cue the suspenseful music. Here’s everything you need to know:

‘To Leslie’ released to critical acclaim, but not wide appeal

Until recently, most Americans hadn’t heard of “To Leslie.” Premiering at South by Southwest in March, the film made just $27,000 at the box office during its limited release.

This month, that changed when some of the biggest names in film threw their weight behind the movie. Paltrow praised the film on Instagram, saying Riseborough should win every award, including “all the ones that haven’t been invented yet.”

Adams hosted a conversation with Riseborough and director Michael Morris, calling the movie an “amazing, amazing feat of filmmaking.”

Kate Winslet, Jennifer Aniston, Edward Norton and Charlize Theron have all also publicly supported the film in various ways, through screenings or moderated discussions.

Meanwhile, on Twitter, other actors have posted almost identical statements supporting the film, calling it a “small film with a giant heart.” Some have likened it to a copy-and-paste job.

Riseborough’s grassroots-esque campaign isn’t new

Though a celebrity-backed campaign isn’t strictly a grassroots effort, the push for Riseborough and “To Leslie” is akin to one. Rarely do celebrities come out with this type of support for a film they don’t star in, making Riseborough’s rapid ascent unique.

But this isn’t the first time an actor has publicly attempted an Oscars push on their own. A decade ago, actress Melissa Leo staged her own photoshoot and took out her own “For Your Consideration” advertisements. Leo at the time was nominated for best supporting actress for her role in 2010’s “The Fighter.”

“This entire awards process, to some degree, is about pimping yourself out,” she told the New York Times in 2011. Leo went on to win the award.

Industry-watchers have noted that soliciting votes is often done to level a playing field — in this case, bring attention to a small-budget, little-known film. The difference now is social media, making this push public rather than one done behind closed doors.

And yet, not every actor has the kind of connections Riseborough does. Critics of the nominations have pointed out that Viola Davis (“The Woman King”) and Danielle Deadwyler (“Till”), two Black actresses who were considered frontrunners, were not nominated for the award. (Both films also drew larger audiences to the box office.)

The Academy’s diversity problem has long been discussed and dissected. And while Riseborough is not at fault for the snubs, some have pointed out that the campaign behind her displays just how much of an advantage it is to have famous White friends.

The Academy’s investigation has more people talking

On Friday, the Academy announced a “review of the campaign procedures around this year’s nominees,” according to a statement obtained by CNN.

The Academy didn’t specifically mention Riseborough, or the very public celebrity push for her nomination. But many people are connecting those dots.

Christina Ricci, star of the Emmy-nominated show “Yellowjackets,” called the Academy’s decision to review the procedures “very backward,” in a now-deleted Instagram post.

“Seems hilarious that the ‘surprise nomination’ (meaning tons of money wasn’t spent to position this actress) of a legitimately brilliant performance is being met with an investigation,” she wrote, according to Deadline. “So it’s only the films and actors that can afford the campaigns that deserve recognition? Feels elitist and exclusive.”

Whether Riseborough’s nomination will actually be overturned is hard to say. There is precedent — in 2014, composer Bruce Broughton received an Oscar nomination for the title song from “Alone Yet Not Alone” and was later disqualified over his campaign.

Regardless of celebrity backing, Riseborough faces fierce competition in the category, from the likes of Michelle Yeoh (“Everything Everywhere All at Once”) and Cate Blanchett (Tár).

As the melee plays out, one thing is for sure: you’re gonna need more popcorn.

Questions are swirling around Andrea Riseborough’s Oscar nomination