A man believed to be the oldest dialysis patient in the world has celebrated his 100th birthday.

Sidney Benjamin has received dialysis treatment at St John and St Elizabeth Hospital in St John’s Wood three times a week for the past four years.

Staff cut a cake and placed balloons around his bed, when he came in for his treatment last Thursday, a day after he celebrated his landmark birthday with a meal at a kosher restaurant.

He joked that being tee-total is the secret to his long life, as he turned down the champagne offered by staff and celebrated with a flute of water.

He said: “It’s great reaching 100 years. I never expected to arrive at three figures.”

He received letters from the Queen and 10 Downing Street to wish him a happy birthday, as well as a card signed by staff and patients on his ward.

Nurse Michelle Powley, renal unit manager, said: “I have never heard of someone on dialysis reaching 100 before.

“We’ve done some research online and we think Sidney is the only one. He’s one of the easiest people to look after, he never complains and he is co-operative and independent.

“He’s got a real sense of humour and he’s always joking with the nurses.”

The former watch and clockmaker says he only gave up working from home last year.

Born in east London, he learned his trade aged 14 before opening a business in the Holloway Road, Islington.

He was called to serve with the RAF as an engineer during the war, and continued his business after being demobbed.

Mr Benjamin, who suffers from chronic renal failure, lives in a flat in Finchley, with support from a carer. He had a son, Daniel, when he was 27 who is no longer alive.