Montserrat’s niece, who shares the same name, remembered the enormous fun and late nights rehearsing in London at Freddie’s West Kensington mansion.

She said: “We were in Freddie’s house,  there were days when we were maybe there until six or seven in the morning, because after dinner they went to the piano and he played the piano and sang, and Montserrat improvised. Truly it was an incredible party.

“For Freddie, Montserrat was something out of this world. He had such love and admiration for her, he was always watching to make sure everything was perfect for her. When we arrived at the hotel, there were roses in every room, we wanted for nothing.”

While the pair were still working on their collaboration, Montserrat also gave a performance at the Royal Opera House, with Freddie in attendance.

Freddie described how she “embarrassed” him by introducing him to the crowd: “I was sitting there with my tuxedo and I had to stand up and take a bow. She blew kisses to me and I blew kisses back.”

Montserrat said: “The audience loved it. They went crazy at the Royal Opera House.”