Joel Mason (pictured) was raised by Richard Mason, founder of price comparison website MoneySuperMarket, for two decades before discovering tycoon wasn't his real father

One of three boys tricked into believing a multi-millionaire businessman was their real father has broken his silence to reveal how his mother hid the truth from them for two decades.

Joel Mason was raised by Richard Mason, founder of the price comparison website MoneySuperMarket, until the tycoon learned the truth when doctors told him he had been infertile since birth and couldn't be the boys' father.

Now as Mr Mason's ex-wife Kate is ordered to pay him £250,000 following an extraordinary legal case that has allowed her to keep the identity of the real father a secret, his son Joel says he has no desire to find out who his biological dad is.

Speaking for the first time in a heart-breaking interview, Joel, 19, told MailOnline: 'I've not fallen out with Mum over this. We're all OK. She had just had an unhappy marriage and she wanted kids. And here we are. I never knew until a couple of years ago that Richard wasn't my real dad.'

Joel admitted to having a difficult relationship with Mr Mason, who he hasn't spoken to for three years, but says he will always consider the businessman his real dad.

'I don't know if I'd call it estranged,' Joel said. 'I wouldn't know what word to use. But I haven't been speaking to him for a number of years because of his behaviour. He's a very manipulative man, not the kind of person you want to be with. I started noticing this when I was 15.

'But he's still my dad and I'm not going to look for my real one. I doubt he [his biological father] even knows we exist. But Richard now wants him to be in our lives and to make contact.'

Devastated Mr Mason never doubted he was the boys' biological dad until two years ago when he was diagnosed with cystic fibrosis - an inherited disease which prevents male sufferers from fathering children naturally.

Richard Mason, pictured with his ex-wife and three sons (left to right Ed, Willem and Joel, circled), raised the boys for 23 years believing they were his until doctors told him he's infertile

The businessman said that his world fell apart when he was diagnosed with cystic fibrosis in 2016 and was told he couldn't be the boys' father. His wife Kate later admitted a four-year affair

Mr Mason, 55, pictured with his third wife Emma at their home in north Wales, says he wants the boys' real father to come forward to put to be the lie the family has been living for years

DNA and other tests later confirmed beyond doubt that the businessman has no biological link to the eldest boy, Willem, now 23, Joel or his twin brother Ed, 19, throwing his life - and his relationship with them - into turmoil.

Mr Mason believes that the same man fathered all three boys during an intermittent four-year affair his wife Kate, 54, embarked on in the late 1990s.

Joel said his mother eventually confessed the adultery in 2016, ten years on from their divorce, when Mr Mason confronted her about the children's paternity.

Joel, who bares an uncanny resemblance to Mr Mason, told of his shock when he and his brothers found out the man who raised them wasn't their natural father - and at first struggled to believe it.

He said: 'When Richard was diagnosed with cystic fibrosis he asked us to do blood tests.

'Myself and my twin Ed agreed, but our elder brother Willem refused. At the time I was in the sixth form at school and I thought it was something he was doing just to get money from my mum.

After divorcing Mr Mason, his ex-wife moved on to a new relationship with Martin Smith (pictured) who is not the boys' (pictured) biological father, until the couple recently separated

Joel said he and his twin brother Ed (right) agreed to a DNA to prove that Mr Mason wasn't their father but their elder brother Willem (left) refused. None of the brothers want their biological father to come forward, says Joel

'At first we questioned it because Richard refused to do a DNA test in front of us or in the court so we thought he was just saying it and had messed with the data.

'But later we tested our DNA against that of Richard's brother, our uncle. We were not blood related to him which meant Richard couldn't be our real dad. That was conclusive, it was the proof we needed.

'It didn't hurt me because he hadn't been my dad for a few years. I felt nothing. It didn't really matter because we were grown up and he and my mum were divorced.'

He added: 'I haven't asked mum who our real dad is, I'm sure she'd tell me but I don't want to know. Mum's single now, she's not remarried.'

Joel (pictured) says he has no desire to find his biological father and that Mr Mason will always be his dad in his eyes

Joel, who is studying Property at Nottingham University, told how he and his family were first made aware that his father had spoken to a Sunday newspaper a few days ago before the article appeared.

He explained: 'We were shocked and surprised it was all being made public. That was his doing. Just something else after the long court battle.

'Richard texted me and my brothers to tell us he had given his story to a paper. We weren't happy he had gone to the papers.

'Ed replied but Will and me didn't. He just wants the attention. He is a big fan of starting a new business. He's known for two years that he's not our real dad so why do all this now?

'Richard wants our real dad to get in touch, but why? I'm not talking to him and Willem is in a similar boat, but Ed is a bit closer to him.

'Mum and dad are only talking through lawyers and I assume our natural father, whoever he is, has not made any contact and no doubt even knows we exist.'

Joel, who comes across as mature, level headed and reasonable, said it was 'a fair deal' his mum had to pay £250,000 back to his dad.

He said: 'That was a fair deal, they [parents] could both give quite compelling arguments and I could see it from both perspectives.'

He told how his mum had invested some of the money from the divorce into property to help ensure her three sons had a comfortable lifestyle.

After the divorce she moved on to a new relationship with Martin Smith, who lived with her in the huge family home overlooking Uttoxeter racecourse in Staffordshire until they recently separated.

Mr Mason's ex-wife Kate (pictured) has been ordered to pay him £250,000 following an extraordinary legal case that has allowed her to keep the identity of the real father a secret

Richard Mason is pictured with his current wife, Emma. The businessman believes that the same man fathered all three boys during an intermittent four-year affair his ex-wife Kate, 54, embarked on with a former colleague in the late 1990s

Joel went on: 'Mum and Martin were together for about nine years but split up a few months ago. He's got twins with his ex-wife, they were one when we met them, now they're 10. He's gone off skiing now with his kids and new missus.'

He said Martin 'definitely is not' his biological father and said he had always been 'more of a friend than a father figure.'

Joel said Martin and his mother didn't split up over the paternity furore, saying: 'The relationship just didn't work. He's moved on and mum's single and in her own.'

He added: 'Martin still lives at the family home but also stays with his mum. It can be a bit difficult at times but they usually maintain a civil relationship.'

Three-times married Mr Mason likened his discovery of not having fathered kids to 'suffering a bereavement'.

Speaking on Good Morning Britain this morning, the entrepreneur said: 'It was like being hit by a hammer. It was like the world had just fallen away. I felt like on the one hand I had just been told I’d got a terminal illness, but finding out the boys weren’t mine were very very hard. They are my children.'

'I never doubted the kids were mine until, things started to happen, make you suspicious, when the diagnosis was given to me. I thought what do I do now? I had always brought them up to be open and honest. I said to them, 'Look, I will never do anything that I don’t want your mum to know about.

'I always thought she was a good mum to them. She’s cold and critical as a person, but I thought she was a good mother to them.'

Defending his decision to take his ex-wife to court, Mr Mason, whose third wife Emma with breast cancer two years ago and had a mastectomy, said: 'I think it was inevitable it was going to happen. This was a lie started 23 years ago by Kate. It has finally blown up. I had to do what was right.

'When the story broke I insisted that all the photos of the boys were toddlers. They're now 19 and 23. I started the action when they were men. They are intelligent boys, well brought up, I paid for private education for them, they know what is right and wrong.'

Touching on his fractured relationship with his sons, the impact the court case has had on them and what he would say to them, Mr Mason told the show: 'I would say, 'Boys I haven’t done, anything wrong. I love you, the biggest hug ever is waiting for you. Kettle waiting to go on, six pack of beer Lets have a cry and a hug and get back to where we were before. And have a word with your mum.'

Mrs Mason, who is currently abroad on holiday with her niece, has remained silent.