In a statement released via her management company, Cook's family said she died of cancer on Wednesday night, the ABC reported.

"It is with great sorrow that her family wish to advise that the much loved Penny Cook, beloved partner, mother, daughter, sister, and dear friend, died peacefully last night, of cancer, surrounded by family," a statement from her agent Mark Morrissey said on behalf of her family.

"The family wish to express their thanks for all messages of condolence forwarded to them," the statement said.

She graduated from Australia's National Institute of Dramatic Art in 1978 and first appeared on Australian TV screens in the soap series The Restless Year.

Cook was perhaps best known for her role as veterinarian Vicky Dean-Bowen in A Country Practice from 1981 to 1985 for which she won a Logie in 1981.

She played the original Dr Elly Fielding in the Ten Network soap E Street from 1989 to 1991, before being replaced in that role by actress Diane Craig.

In 1998 Cook had a daughter called Poppy. She was married to David Lynch and was previously married to broadcaster Clive Robertson.

Cook was a presenter on the Australian travel show The Great Outdoors from 1992 to 1996. She appeared in the police drama Young Lions in 2002.

Cook had a long involvement in the theatre, both as an actress and director, and was involved in nearly 40 stage productions.

In 1979 she helped form the Griffin Theatre Company (Sydney) for which she performed numerous times.

She also appeared in several national tours including Sir Peter Hall's production of Oscar Wilde's An Ideal Husband, and in the John Bell/Richard Tognetti production of The Solder's Tale with the Australian Chamber Orchestra.

Cook was also a spokeswoman for several prominent Australian charities.

A private cremation will be held and a celebration of Ms Cook's life is to be announced at a later date.

Australian Associated Press