Victoria Wood’s brother has defended his decision to publish a “warts-and-all” biography of his late sister – denying he is betraying the comedian.

The book, which is due out later this month, includes extracts from a journal written by the pair’s late father Stanley Wood.

In the private diary, he criticises her for being overweight, details her relationship with an early boyfriend and describes Victoria as being “very glum and morose”.

Victoria Wood died after a battle with cancer (Peter Jordan/PA)

Much-loved comedian and actress Victoria was fiercely private, and the news of her death in April, at the age of 62 from cancer, came as a shock to most people as she kept her illness out of the public eye.

Her brother Chris Foote Wood said the book, called Victoria Wood Comedy Genius – Her Life And Work, would provide “a unique insight into how an overweight, lonely and unhappy girl overcame early difficulties to build her hugely successful career”.

He told the Press Association: “I have only written the truth.

Victoria Wood in Dinnerladies (BBC/PA)

“Victoria was fat and unhappy as a girl – she said so herself in press interviews and on BBC radio’s Desert Island Discs.

“It cannot be a betrayal to tell the truth. It would be a nonsense to leave out Vic’s unhappy childhood. On the contrary, it is all the more to her credit that she overcame these early difficulties to forge her hugely successful career.”

He added: “I am a huge fan of Victoria but I cannot hide the facts.”

The book includes Victoria’s first joke and previously unpublished family photographs of the Acorn Antiques and Dinnerladies star.

Victoria Wood ( Steve Parsons/PA)

Entries from her father’s journal, published in the Sunday Mirror, include the claim she had become “fatter than ever and has more spots”.

It lists how much food she had eaten and said she watched eight hours of television a day.

Chris, who has raised £20,000 through crowdfunding to erect a life-size memorial of Wood in the centre of Bury, Lancashire, said all royalties from the book will be donated to charities his sister supported.