Paul McCartney has shared memories of Doris Day, who died aged 97 on Monday, as a devoted and passionate animal welfare activist

"She was a true star in more ways than one," the ex-Beatle has written on his website. "One of those ways was as a lifelong animal welfare activist."

The late actress and singer was once named 'the Dog Catcher of Beverly Hills' because of her love of animals. She founded the Doris Day Pet Foundation in 1978, which in time became the Doris Day Animal Foundation.

"Visiting her in her Californian home was like going to an animal sanctuary where her many dogs were taken care of in splendid style," McCartney writes.

"She had a heart of gold and was a very funny lady who I shared many laughs with. Her films like Calamity Jane, Move Over, Darling and many others were all incredible and her acting and singing always hit the mark.

"I will miss her but will always remember her twinkling smile and infectious laugh as well as the many great songs and movies she gave us."

In a 2016 Rolling Stone interview, the Liverpudlian quoted his idol as he discussed getting old.

"Doris Day, who I know a little bit, once said to me, ‘Age is an illusion’ …I reminded her of it recently – I was wishing her a happy birthday. People say age is a number. It’s a big number the older you get. But if it doesn’t interfere, I’m not bothered. You can ignore it. That’s what I do."

When I'm sixty-four etc -"You can ignore it. That’s what I do."