Reese Witherspoon has revealed a speech misfire at an awards ceremony cost her a friendship with an A-list actress.

The 'Legally Blonde' star, 48, admitted the mishap happened when she was invited to present an award to a well-respected actress but completely misjudged the tone of the evening - delivering a roast-style speech as she believed it was meant to be a lighthearted event.

She has now admitted to People about her friendship crumbling as a result of her gags at the event: "I'm not even kidding - we're not friends anymore.

"It literally haunts me."

Reese added: "So this friend of mine - who I didn't really know that well, but she was a very serious, proper actress - she asked me to give her an award.

"I had never been to that particular awards ceremony before, and I thought it was like a roast. So I got up and I roasted her.

"(But) the tone was British and elegant and classy. And I was like, 'Remember the time we got laser hair removal?!'"

Despite now seeing the funny side of the incident, the Oscar-winner admitted she remains embarrassed by her error.

She added: "I'm still embarrassed about it. I thought it was so funny, and it was just, I had the wrong audience. It was pretty bad.

"I think (the actress being honoured) doesn't like me anymore... oh well."

Reese recently reflected on the importance of humour in her life.

She said on 'The Tonight Show Starring Jimmy Fallon' about how she instills it in her children: "I think you should embarrass them enough that they're funny later in life."

Jimmy then told her: "You are one of the coolest moms, I would say. Your kids gotta be proud of you, but also, you post (online) that make you embarrassed… I love that about you."

Reese agreed her children - Ava, 25, Deacon, 21, and 12-year-old Tennessee - don't always love what she shares on social media, but she believes it teaches them to take life less seriously.

She said: "I think it's a good thing."