Actress Dame Thora Hird is seriously ill in a nursing home after suffering a stroke.
Dame Thora became a household name through her sitcom roles
The 91-year-old star of BBC One's Last of the Summer Wine became ill at the weekend at her retirement home in south-west London.
Her relatives are now awaiting the results of medical tests to find out how serious her condition is.
"We can confirm that Thora did have a stroke at the weekend," her agent said.
"She is currently being treated in a private nursing home and we are awaiting medical reports."
Dame Thora has become increasingly frail and has wound down her acting in recent years, but has continued to be a popular face on screens.
She is known to millions for starring in sitcoms like 1960s favourite Meet the Wife, playing Thora Blacklock, and In Loving Memory playing Ivy in the late 1970s.
Dame Thora has been in Last of the Summer Wine for almost 20 years
She joined Last of the Summer Wine in 1985, starring as the gossiping Aunt Edie Pegden.
Her most recent appearances are currently being screened on BBC One, with a special show to mark the programme's 30th anniversary expected to be aired in April.
She won acclaim and awards - including best actress at the Bafta TV Awards - after starring in Alan Bennett's mini-series Talking Heads in 1987.
She repeated her Bafta success when she played a 99-year-old nursing home resident in Talking Heads 2 in 1998.
Her third Bafta best actress award came the following year for TV movie Lost for Words, in which she starred alongside Pete Postlethwaite.
Born in Morecambe, Lancashire, she made her acting debut at the age of two months in 1911 when she was carried onto the stage in a play directed by her father.
She began making movie appearances in the 1940s and appeared in more than 100 films, including The Entertainer with Laurence Olivier.
Her religious convictions also led her to present Sunday TV shows such as Praise Be. She was made a dame in 1993.
Her husband Jimmy Scott died following a stroke in 1994.