The racist photo from Virginia Gov. Ralph Northam's 1984 yearbook was reportedly surfaced by an ex-classmate offended by Northam's recent comments about abortion.

The picture's existence was first published by Big League Politics, and sources from the website told The Washington Post that the tip came from Northam's former classmate or classmates.

Northam first came under fire last week as he defended a Virginia bill that would roll back restrictions on late-term abortions. Abortion opponents accused Northam of supporting infanticide.

A racist photo that embroiled Virginia Gov. Ralph Northam in controversy over the weekend reportedly surfaced due to one of Northam's former classmates, who was enraged about his recent comments about abortion.

The emergence of a photo on Northam's yearbook page — featuring one person in blackface and one person in a Ku Klux Klan-style robe and hood — sparked bipartisan demands that Northam resign as governor.

Northam initially confessed to appearing in the photo and apologized for it, before walking back the admission on Saturday and denying he was part of it. Further, in a bizarre press conference, Northam admitted he had previously worn blackface as part of a Michael Jackson costume.

The news outlet that first reported on the existence of the photo was the website Big League Politics, whose editor in chief told The Washington Post that the tip came from a "concerned citizen."

Read more: Another photo in Gov. Ralph Northam's 1984 yearbook shows a man in blackface

Virginia Governor Ralph Northam speaks with reporters at a press conference at the Governor's mansion on February 2, 2019 in Richmond, Virginia. Northam denies allegations that he is pictured in a yearbook photo wearing racist attire. Alex Edelman/Getty Images

"It's very easy to explain," 29-year-old Patrick Howley told The Post. "A concerned citizen, not a political opponent, came to us and pointed this out. I was very offended [by the photo] because I don't like racism."

But The Post reported that two other sources from Big League Politics said the source was a former medical school classmate — or classmates — who grew enraged by an earlier controversy involving Northam's comments on abortion.

Last Wednesday, Northam appeared on a radio show to discuss a hotly contested abortion bill that would have rolled back several legal requirements around third-trimester abortions.

In his interview, Northam was asked to discuss a scenario in which a child was born after a failed abortion attempt.

"The infant would be resuscitated if that's what the mother and the family desired, and then a discussion would ensue between the physicians and the mother," he said.

Abortion opponents railed against Northam's remarks, accusing him of supporting infanticide. Among those offended was apparently at least one former classmate of Northam's, according to The Post.

"The revelations about Ralph Northam's racist past were absolutely driven by his medical school classmate's anger over his recent very public support for infanticide," one Big League Politics source told the newspaper.

Some critics seized on Big League Politics' reported ties to GOP operatives, but Howley has described the news outlet as politically "independent."

Read more: 'It is definitely not me': Virginia Gov. Ralph Northam refuses to resign and denies he appeared in racist photo despite later blackface incident

Though Northam has suggested that the blackface photo was mistakenly posted on his yearbook page, his critics — including his fellow Democrats — have demanded that he step down, arguing that Virginians' trust in their governor is irreparably broken.

"It doesn't matter whether he was in the photo or not in the photo at this point. We have to close that chapter. We have to move Virginia forward," former Virginia Gov. Terry McAuliffe told CNN's "State of the Union" on Sunday. "Ralph will to the right thing for the Commonwealth of Virginia."

As of Sunday evening, Northam was huddled in a meeting with staff members, as he weighed whether to resign or continue battling to clear his name, The Washington Post reported.