Olympic hopeful Tom Daley has given an emotional account about the death of his father.

The diver recalled how he broke down and sobbed at his father Rob's bedside, holding his hand for half an hour after he died.

The 17-year-old has dedicated his performance at the 2012 Games to his dad, saying that every time he emerges from the water he expects to see him at the poolside.

In his book, My Story - which has been serialised in the Review section of the Mail on Sunday, the teen retraces painful memories about his father's protracted illness.

Mr Daley had had vowed to survive long enough to watch Tom compete in the Olympics. But the 40-year-old was denied his dream when he died peacefully with his family at his bedside in May last year.

Mr Daley followed his son's promising career around the world despite his illness and had become a familiar figure at the poolside.

He was first diagnosed in 2006 with a fist-sized brain tumour, of which surgeons were originally able to remove 80%. But the tumour returned and his health had deteriorated since February 2011.

Daley is among Britain's best hopes for a gold rush at the games later this year.

"As I climb out of the water, I always think about Dad," writes Daley.

"He was at almost every training session and competition that I did until he died last May, and every time I train I expect to see him sitting by the poolside, grinning and cracking jokes, making everyone around him laugh.

"He was not only my dad; he was my best friend, sounding board, taxi driver and biggest champion.

"When I jump from the board at London 2012 Olympics in a few week's time, it will be for him."

In his book, he describes his father's passion for his diving career.

Mr Daley "never let on about his condition", writes Daley, adding: "He still took me to training even when he was tired and behaved just like normal."

Despite being painfully ill, in April last year, Mr Daley managed a trip to Sheffield to watch his son dive for the last time.

Daley said: "I went to see him in the gallery and he was in floods of tears. It was really emotional.

"I don't think he ever knew that it would be his last competition and how ill he was.

"No one told him what the cancer might do because they never wanted him to give up."

Shortly afterwards Daley took a turn for the worse and his son had to come home early from a competition in Mexico to be by his bedside.

Daley said: "She (Mum) told me they had booked a flight and I needed to be at the airport in an hour. 'You need to, Tom. Your dad, he's not got long left', she told me.

"I felt numb and unable to comprehend. Part of me still felt he would pick himself up again. He'd made light of it for so many years and fought so hard and defied the doctors so many times.

"Within 24 hours I was home; Dad was in a bed in the front room and I just saw how ill he was.

"All my family - grandparents, aunts and uncles were around the bed.

"He couldn't do anything and was struggling to keep his eyes open and he seemed unaware of what was going on.

"I was really shocked and felt very emotional.

"Everyone would have to go to the kitchen at regular intervals for a cry."

The teen described how on his 17th birthday, his father cried when he couldn't get out of bed to see his son getting behind the drivers seat of a car for the first time.

He died a few days later.

Daley wrote: "We all whispered our goodbyes to him while we thought he could hear us.

"I told him how much I loved him and I thanked him for everything he had done for me.

"At about 9pm we decided to take off the oxygen mask. Then the awful waiting. Eventually his breathing slowed until finally the inhalations just stopped.

"Everyone started crying. I just looked at him. I could not believe it.

"I sat holding his hand for the next half an hour. As the tears ran down my face I stroked his head. He just looked as if he was sleeping.

"I let go and gave him one final hug, feeling his once strong body in my arms. I went into the kitchen and sobbed with everyone else."