Britney Spears' Mom Killed a 12-year-old Boy in 1975

Lynne Spears -- mother of Britney -- once killed a 12-year-old boy, a new report claims.

According to US tabloid the National Enquirer, Lynne ran over a bike-riding young boy with her car, causing his untimely death.

The Spears matriarch is still said to be haunted by the accident, which occured in 1975.

A source told the publication, "To this day, Lynne hasn't gotten over what she did. She gets that terrified look in her eye when she is thinking about it.

"She has told only a few people about the accident and always says, 'Please don't think I'm a bad person.'"

Lynne was 20 when the tragedy occurred in her hometown of Kentwood, La., during the same year she married Jamie Spears.

When the accident happened, Lynne was driving Britney's brother to the hospital after he'd suffered an injury.

"It bothers Lynne still to this day," said a representative for Lynne Spears.

"She really doesn't like to talk about it. She just wanted to forget that it ever happened - but she can't."