Top US Democrats have called on Virginia Governor Ralph Northam to resign, after his 1984 student yearbook page emerged showing a racist photo.
Former Vice-President Joe Biden joined a chorus of condemnation, saying Mr Northam had lost all moral authority.
The 59-year-old Democrat has apologised for the image. Black politicians in Virginia called it “disgusting” and Republicans also urged him to resign.
The picture showed a man in blackface and another man in Ku Klux Klan robes.
Mr Northam was elected governor of Virginia in November 2017.
How has this come about?
Mr Northam’s yearbook page, which came from the paediatric neurologist’s time at Eastern Virginia Medical School, was first published by conservative website Big League Politics.
The Virginian-Pilot newspaper tweeted a picture of the page which it said it obtained from the medical school library.
An official from the medical school verified the photo and told the Huffington Post that it had come from a “student-produced publication”.
The page, which features Mr Northam’s full name and photos of the future doctor and politician, also included a quote from a Willie Nelson song that read: “There are more old drunks than old doctors in this world so I think I’ll have another beer.”
Mr Northam, who was aged about 25 at the time, did not elaborate on which costume he was wearing, but said he appeared in a photograph that was “clearly racist and offensive”.
What has Northam said?
“I am deeply sorry for the decision I made to appear as I did in this photo and for the hurt that decision caused then and now,” Mr Northam said in a statement after the image was made public.
“I understand how this decision shakes Virginians’ faith in that commitment.”
Mr Northam later released a video statement via Twitter in which he said he was “deeply sorry” for the offence the image had caused.
Before he was elected governor, Mr Northam served for a decade as a Virginia state legislator.
His responsibilities as governor include implementing state laws, restoring voting rights for individuals who have had them withdrawn and issuing pardons.
What is the reaction?
The Virginia Legislative Black Caucus, which comprises African Americans elected to the state legislature, described the images as “disgusting, reprehensible and offensive”.
“These pictures rip off the scabs of an excruciatingly painful history and are a piercing reminder of this nation’s sins. Those who would excuse the pictures are just as culpable,” it said in a statement.
In a tweet, Mr Biden said Mr Northam should resign immediately.
Calls for his resignation also came from four Democratic candidates for president – Senators Kirsten Gillibrand, Kamala Harris and Cory Booker, and Texan mayor Julian Castro.
The photo also prompted a swift backlash from conservatives, including Jack Wilson, the chairman of the Republican Party of Virginia, who called on Mr Northam to step down.
“Racism has no place in Virginia,” he said in a statement. “These pictures are wholly inappropriate. If Governor Northam appeared in blackface or dressed in a KKK robe, he should resign immediately.”
Democratic Senator Elizabeth Warren, who is considering a presidential run in 2020, also called for Mr Northam to resign.
The Ku Klux Klan is one of the oldest and most infamous hate groups in the US, and has targeted African Americans, Jews, Catholics and immigrants, according to the Southern Poverty Law Center, which tracks hate groups.
The group has a long history, with KKK membership peaking in the 1920s.