Britney Spears has confirmed she is writing a book, saying the process has been “healing and therapeutic”.

The Toxic singer, 40, said there were parts of her life she had never been able to “express openly” as she shared the news on social media.

Writing on Instagram, she said: “I’m writing a book at the moment and as it’s actually healing and therapeutic.

“It’s also hard bringing up past events in my life…I’ve never been able to express openly.”

She added: “I can only imagine that I do sound childish but I was extremely young when those events took place … and addressing it now, I’m sure it seems irrelevant to most.

“I’m completely aware of that.

“But instead of using my heart I’m using the intellectual approach.”

The pop star’s controversial conservatorship, which controlled many aspects of her life including her finances, was ended last November.

She was placed under the legal arrangement in 2008 amid substance abuse and mental issues.

The decision to end the conservatorship closed one of the most controversial chapters in modern pop music history and handed Spears the keys to her estimated 60 million dollar (£45 million) estate.

Spears’ fiance Sam Asghari, 28, commented on her post, saying he would be “buying the first copy”.