A white local news anchor has resigned after referring to herself as a 'news n***a' in a Twitter exchange with a black man she was contacting for a story.

Valerie Hoff, 54, was trying to obtain a copy of a video which showed a white police officer punching a black motorist when she made the comment to Curtis Rivers on April 13.

He shared a screen grab of the comment with followers, prompting Hoff, a mother-of-two from Atlanta, Georgia, to apologize and later resign from her role at 11 Alive, an Atlanta-based ABC affiliate.

Their exchange began when Rivers posted footage of Gwinnett County Police Department officer Sgt. Michael Bongiovanni punching student Demetrius Hollins in the face during a traffic stop.

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Valerie Hoff, 54, resigned from her role at 11 Alive after using the N word in a Twitter exchange with Curtis Rivers

The footage triggered Bongiovanni's termination from the department. Another officer was also fired over the incident.

After sharing the video which he came across in a group chat, Rivers told Twitter followers that a lot of 'news n***as' had been contacting him requesting permission to use it in coverage.

Hoff made contact with him through a direct message where she tried to obtain a copy.

'Please call this news n***a. Lol I'm with 11 Alive,' she wrote.

Rivers was at first amused and answered the journalist's questions without hesitation.

Minutes later however, he commented: 'I just looked through your photos on twitter and realize you aren't black but called me a n***a.'

Hoff shot back immediately. 'No, I called myself one,' she wrote, going on to explain that she was a 'news lady' and apologizing for any offence.

Rivers responded by requesting contact details for her 'manager or lawyer'.

Hoff launched their private conversation by introducing herself as a 'news n***a'. Rivers was at first amused but took offence when he realized she was white

The exchange was picked up by other social media users who lampooned Hoff's use of the word.

'I'm just confused because even if you were repeating what he said, censor yourself,' said one.

'So public or private, it's disgusting. Waiting to see how u try to justify the reason for u using the N word?' another asked.

11 Alive initially suspended Hoff but she announced her resignation on Saturday.

She has since continued tweeting about the issue, insisting her comment was made in 'bad judgement' but with good intentions.

Hoff was trying to obtain a copy of this video which showed a Georgia police officer punch a black student during a traffic stop

Student Demetrius Hollins was left with a bloodied nose after the attack. Gwinnett County Police Department Sgt. Michael Bongiovanni was fired over the incident

Hoff apologized immediately but resigned over the weekend. She has since tried to explain herself, telling Twitter followers the remark was 'stupid' but made with good intentions

She also claimed Rivers threw their conversation out of context, that he tried to sell the video to her and that she has 'so much more to tell'.

In a statement to The Atlanta Journal Constitution, 11 Alive boss John Deushane said: '1Alive does not tolerate any form of racial insensitivity and aggressively enforces our standard policies. We acted promptly to address this situation.

'Valerie Hoff has chosen to resign and apologizes for her actions. 11Alive is committed to treating the communities we serve with dignity and respect.'