Viewers will see the actress's character Dot Branning bow out from Walford later this week as the Albert Square favourite is struggling to move on from the death of Heather Trott.
Last month, reports suggested that the 85-year-old had asked for six months away from filming.
However, Brown told The Scottish Sun: "According to reports, I've taken a six-month break to write my autobiography. I don't know how long I will be out. It was never stated when I filmed my last scenes in March.
"I have signed a contract to write a book which I started 10 years ago. I've only done three and a half chapters, so I have quite a bit to go."
Brown continued: "I've also lost my friend Barbara Windsor, who was Peggy, of course. Her dressing room was next door and she was always popping in for a coffee. She is a lovely one for the gossip. I learned everything that was going on from her.
"Then Polly Perkins came into it to play my sister Rose. Now she's away too. So I have no idea if I will go back. I really don't know. No-one is indispensable."
An EastEnders spokesperson said: "June Brown is taking a break from EastEnders. She will be completing her autobiography, and will return in the not too distant future."
Brown has portrayed the role of Dot on and off since 1985.