Kensington Palace’s former head gardener recounted stories of Diana Princess of Wales singing Abba songs and jogging past staff, after attending the “incredible” unveiling of her statue.

Graham Dillamore, now deputy head of gardens and estates at Historic Royal Palaces, said the Duke of Cambridge and the Duke of Sussex jointly revealing the statue of their mother was a symbol of “unity”.

He part-project managed the redesign of the Sunken Garden which was planted with flowers and plants to complement the statue – featuring the princess with three children – created by sculptor Ian Rank-Broadley.

Mr Dillamore had one wish following the unveiling of the statue: “I hope she likes it.”

He knows the Sunken Garden well as he was head gardener at Kensington Palace from 1984 to 1991 when Diana was bringing up William and Harry at the palace with Charles.

Mr Dillamore said he had “lots of flashbacks” going back for the unveiling ceremony and seeing the royal brothers, adding: “I think it was just an incredible moment when they pulled that cord off the statue to reveal such a wonderful thing – there was a great, I thought, unity there.”

Casting his mind back to when William and Harry were young boys, he said occasionally they would “get pushed around with nanny now and again into the garden and we’d see them grow up in the gardens here”.

Describing moments when health-conscious Diana would stop to say hello, he added: “We would be working in here – not just me but several of us, working from time to time – and Diana, the Princess of Wales would often jog past or jog back.

“She was quite quick, a very fast runner, but if she saw us the princess would often come in, share a joke with us, see how we were.

“She was often very concerned about how we were, whether we were too hot or too cold and was everyone well, and very interested in our lives and what we were doing, very sincere as well – so some very happy memories there.”

The Sunken Garden was a favourite spot for Diana and she sometimes arrived singing a favourite tune, Mr Dillamore said.

He added: “Those golden moments at seven, eight o’clock in the morning when it was very peaceful and you could just hear the birds chirping in the background and the princess would come skipping down those steps behind me.”

He laughed: “Singing some Abba song I couldn’t stand, but we would be honoured.”