A spinster who quietly amassed a £2.5 million fortune has left almost all of it to London Zoo.

Delene Welch, 77, lived modestly in a Belsize Park semi with her two cats and would not take holidays because she did not want to leave her beloved pets with strangers.

Despite sitting on assets worth millions built up during her career as a property lawyer, her only extravagance was to feed her cats fillet steak.

Even her closest friends had no idea of her wealth until her will was published after she died from lung cancer in February.

Welch left £45,000 to friends and relatives, £20,000 to an animal home and gave the rest of her money, nearly £2.4 million, to the Regent's Park zoo.

Her best friends, twins Mavis and Audrey Hirschberg, 71, said Welch's love of animals had been the dominant influence of her life.

"We knew her for 30 years and she was a beautiful person with a superbly sharp mind and a wonderful sense of humour, we loved her dearly," said Mavis Hirschberg.

"She did not live extravagantly and never even went on holiday because of her cats, so all her money was saved up.

"We knew she wanted to give it to animals in some shape or form but we simply had no idea how much money would be involved.

"It came as a great shock to us. If she had left one million we would have been surprised."

Welch was one of the first female solicitors to reach the top of her profession when she was made a partner of law firm Tarlo Lyons.

She spent as much time as she could after she retired working as a volunteer for London Zoo.

Hirschberg, of Hove, added: "She loved every animal from a mouse to an elephant but most of all she loved her cats, both big and small.

"It is fair to say she had more time for animals than for a lot of human beings."