Britney Spears hits out at sister Jamie Lynn after being accused of locking her in a room with a knife

Britney Spears has been accused by younger sister Jamie Lynn Spears of locking her in a room and “grabbing a knife” in her memoir Things I Should Have Said.

In the tell-all book the former Zoey 101 star labelled her 40-year-old sibling’s behaviour as “erratic, paranoid and spiralling”.

But after Jamie Lynn’s interview with Juju Chang on Wednesday's Nightline, the Oops!... I Did It Again hitmaker took to Twitter to defend herself, in which she slammed the 30-year-old actor the “lowest” of low.

In a lengthy Twitter post, Britney wrote: “Jamie Lynn .. congrats babe! You've stooped to a whole new level of LOW .. I've never been around you ever with a knife or would I ever even think to do such!!!

“The only knife I ever saw you with at home was cutting the biggest pieces of squash I ever saw in my life and it was way too big for me to cut.”

Britney went on to plead with Jamie Lynn to stop making “crazy lies” to sell “Hollywood books”.

Britney continued: “So please please stop with these crazy lies for the Hollywood books!!!'

“NOW and only NOW I do know only a scum person would make up such things about someone... I'm actually very confused about you making that up because it's honestly not like you at all !!!

“Around the kids???? Jamie Lynn, seriously??? Come on !!! Congrats on introducing your older sister the concept of getting LOW ... LOWER ... LOWEST ... because you win on that one, babe !!!”

In Jamie Lynn’s interview with Juju Chang about the contents of her latest book, she opened up about feeling “scared” and not feeling safe around her sister, and during the knife claim incident.

“I was scared. That was a moment I had. I also was fearful to really say anything because I didn't want to upset anybody, but I also was so upset that she didn't feel safe”, Jamie opened up.

The row comes in the wake of the end of Britney’s conservatorship, which saw her father, Jamie, removed as conservator.

Britney - who has sons Jayden, 15, and Sean, 16, with ex Kevin Federline - hopes to move on with her life, as she has previously opened up about expanding her family with fiancé Sam Asghari.