In November, The Washington Post reported that Mark Wahlberg was being paid "at least US$2 million for approximately 10 days of work, according to a person familiar with the negotiations who was not authorised to speak about them publicly".
The source said that Williams was paid "a figure in the hundreds of thousands of dollars" for the reshoots.
Director Ridley Scott seemed to suggest that The Washington Post report was inaccurate though when he spoke to the paper in December.
"Everyone did it for nothing," Scott told the publication. "They all came in for free."
In the same USA Today piece, Williams said she agreed to reshoot the scenes for free because she "would do anything" for Ridley Scott.
"I hated that this man's time and expertise and gentlemanly-ness was going to be kind of for naught," she said.
"So when I got the phone call about the change of plans I was thrilled. I was enlivened, it picked me up off the couch a little bit and got me excited.
"I said I'd be wherever they needed me, whenever they needed me. And they could have my salary, they could have my holiday, whatever they wanted. Because I appreciated so much that they were making this massive effort."
All The Money In The World was nominated for three Golden Globes (Best Supporting Actor for Christopher Plummer, Best Director for Ridley Scott and Best Performance by an Actress for Michelle Williams) but didn't win any at the awards on Monday.
But the salary discrepancy was a much talked about issue after the Globes thanks to a tweet from Melissa Silverstein, the founder of Women and Hollywood.
"On the day after display of female power at the #goldenglobes, I learned that there was an egregious pay gap between Michelle Williams and Mark Wahlberg for the All The Money In The World reshoot," Silverstein tweeted.
"Did they think this wouldn't come out? Unacceptable #TimesUp"
The tweet gained traction after it was retweeted by Jessica Chastain, who added: "I heard for the reshoot she got $80 a day compared to his MILLIONS. Would anyone like to clarify? I really hope that with everything coming to light, she was paid fairly. She's a brilliant actress and is wonderful in the film."
Many social media users questioned Silverstein's claim but she wrote that her source is "very reliable" and wrote that Williams and Wahlberg originally agreed to work for nothing but Wahlberg later negotiated a fee for the reshoot.
"That is what I was told," Silverstein tweeted. "She got a per diem and he got an additional fee."
Sony Pictures and Mark Wahlberg are yet to comment on the reported discrepancy, and let's be honest, they probably won't.