A donor has left £143,000 to an RSPCA branch in Wiltshire, sparking a search for people who knew her.
The legacy to the North Wiltshire branch was left by Helene Adele Lisbeth Klein, who lived on York Road in Swindon and died in February 2014.
Manager Richard Clowes said the RSPCA wanted to find out more about the benefactor "in order to pay tribute to her properly".
"It would be great to have a Helene Klein cattery or dog block," he added.
The money is expected to be used towards a £3m building project for an animal centre with veterinary clinic to rehabilitate and then rehome animals rescued in the branch area.
"Sadly, no-one at the RSPCA branch seems to have known Helene but we are all incredibly grateful that she knew about us and left this generous legacy in her will," said Mr Clowes.
"As far as we know, she did not leave any pets when she died, but perhaps she had friends or neighbours who could tell us more about her.
"Was she a cat lover or a dog devotee or did she simply love all animals equally? Any information would be great."