Campaigners are appealing for clemency for an Alabama father who shot and killed the man who sexually abused his daughter when she was just a child.

Last November, Jay Maynor, 43, pleaded guilty to shooting and killing 59-year-old Raymond Earl Brooks in June 2014.

He took the decision partly in order to stop his daughter having to relive her abuse experience before the court. Maynor, from the city of Cullman, was sentenced to 40 years in prison.

Raymond Earl Brooks was shot and killed in June 2014 (YouTube)

Now, a campaign has been started by his friends and family, urging President Barack Obama and Alabama Governor Robert Bentley to intervene.

“Jay Maynor has been sentenced to 40 years in prison for killing his daughter's rapist,” says a petition posted on Change.org, which has been signed by around 8,000 people.

“Jay is not a threat to society. He is a good man. We would like to see him set free or at minimum a lesser sentence.”

Maynor’s daughter, Julia, who is now aged 24, was repeatedly sexually assaulted by Brooks when she was a child. Brooks was her adoptive grandfather.

Brooks pleaded guilty to abuse charges in 2002 and served 27 months of a five-year sentence.

“Basically he took it so that I didn’t have to relive the molestation and also be on the stand in front of a bunch of people talking about and bringing back memories of the molestation,” Maynor’s daughter told AL.com when her father was sentenced.

“My father was protecting me, like a father should do. He is an amazing father - actually the best. He loves us so much.”

Reports said that the 2014 shooting was prompted by a conversation Maynor had with his daughter about the abuse. “It was just something I said out of anger to my father,” she said.