Victoria Wood kept her illness secret from some of her colleagues, a fellow actor has said.
The 62-year-old comedian, actress and writer died at home with her family after a short battle with cancer.
Duncan Preston, who appeared with her in the BBC sitcom Dinnerladies and As Seen On TV, told the Daily Mail he had no idea she was ill until her family called him with news of her death.
"I don't think many people did know," he said. "She'd had cancer for about six months."
The 69-year-old Emmerdale actor called her a "champion of the common people" and writing in the Daily Mirror he said: "I am shocked. All I know is it's a great loss to comedy in this country. She was a very special writer and the world has lost a great, great comedienne."
Wood's close friend and writing partner Julie Walters also paid tribute to her loss as describing her loss as "incalculable".
Walters said in a statement: "Too heart-sore to comment. The loss of her is incalculable."
The pair forged a lifelong friendship while auditioning at Manchester Polytechnic's student theatre as teenagers and went on to collaborate frequently.
Comedian Caroline Aherne said Wood had a "rare gift of making us laugh at the mundanities of life with a humour that was never cruel and only ever warm. A true comic genius".
Impressionist Rory Bremner said: "No. No. This is too much. Now lovely, warm, funny, brilliantly talented Victoria Wood has gone. Words, songs, plays, she wrote the lot. So sad."
Broadcaster Esther Rantzen called her "one of our greatest comic writers and performers".
Wood, born in Prestwich, Lancashire, was well known for her comedy series Victoria Wood: As Seen On TV, as well as her role in sitcom Dinnerladies and her TV special Victoria Wood With All The Trimmings.
She received a special Bafta tribute award in 2005 and in 1997 she was made an OBE in the Queen's Birthday Honours, later being made a CBE in 2008.
Her older brother spoke of the shock of her death, saying it "has robbed us of one of the brightest talents of our generation".
Chris Foote Wood, 75, added: "I am hugely proud of what my sister has done so successfully in different fields of entertainment. It has been a privilege to have her as a sister, and particularly to have been able to observe at first-hand how she developed her career from the earliest beginnings.
"Victoria's two children, my niece Grace and nephew Henry (Durham) will be absolutely devastated to lose their mother at such a relatively young age."
Wood's long-term manager and friend Phil McIntyre said: "Victoria has been a part of our lives as a friend, devoted mother and national treasure for 30 years.
"She was always modest, generous and undemanding. A super person and a super and unique talent. There will be an unfillable void left on all levels and we will miss her deeply."