Jamie Lynn Spears has reportedly unfollowed Kevin Federline over his new memoir

According to Us Weekly, the 34-year-old star stopped following her former brother-in-law on Instagram, along with his wife Victoria Prince.

In the memoir, Kevin, 47, shared two lengthy texts which he has alleged were sent from Jamie Lynn to Victoria about his sons Sean Preston, now, 20, and Jayden James, 19, who he had with the Toxic hitmaker.

Referencing the 43-year-old pop star "lashing out" at her kids in public, he claimed that Jamie Lynn wrote: "Honestly, this makes me want to cry because I feel for those boys so much.

"I'm her little sister by 10 years, and I can't imagine what her actual children must feel like at times, but I am familiar with the feeling of being a dingy trying to survive in a wave caused by another's ship, feeling like you have to rescue yourself.

"I always wanted her to get better, especially for the boys."

He also alleged that the Zoey 101 star said she "started to resent" her sister for her actions, as well as purportedly saying there isn't "enough money or material things in the world that would be enough to repay" Kevin and Victoria for raising the children.

When asked by Us Weekly if he had Jamie Lynn's permission to share the texts in his book, he responded: "I don't want to comment on that."

Last month, a source told the outlet that Britney and Jamie Lynn were "doing a lot better" despite falling out over the years.

The insider said they were "planning on getting together soon", adding: "The girls decided to keep their problems out of the public eye."

Another source said: "They really love one another, but they can be hardheaded siblings."

Kevin has been forced to defend his new memoir against claims that he is trying to profit from Britney's struggles, as the book makes a series of allegations about his 43-year-old pop star ex's behaviour, including claims she was "drunk as hell" around their children and once appeared at their bedroom door holding a knife.

Britney has dismissed the book as "gaslighting" and accused Kevin of "profiting off my pain," saying on Instagram: "If you really love someone then you don't help them by humiliating them."

Speaking to the Daily Mail, Kevin argued: "Everybody's concerned about (Britney), right? That's part of the reason why I'm doing this.

"That's why I came out with a cry for help. We've tried to handle things privately for so long that I felt the need to come forward and really try to gain some support for the family, the boys and her. It's just needed. I feel like the clock is ticking."