Talking to the News of the World, Murs-Hart admitted that he hasn't spoken to the singer since he missed his wedding for the semi-final of The X Factor last year. He also suggested that fame has changed his brother.
Speaking of his wedding, he said: "Something was missing and that was Olly. It's clear people like Simon Cowell are more important to him than me. He's a self-absorbed sell-out. Our family was torn apart because of The X Factor. Things have got to the point where if I have children, I don't even want Olly to meet them.
"I watch my brother - the same person I shared a womb with - on TV now and it's like I don't even know who he is. I understand why Olly wasn't at the wedding. It clashed with the X Factor semi-final and singing has been his dream for years.
"But what hurt was that he never even told me himself he wasn't going to be able to be my best man. I kept reading how Olly had said he was 'gutted' he couldn't make it, but when the wedding came I had my mobile in my pocket all day hoping he would call or even text to say 'good luck' or 'congratulations'. I never heard from him. It was heartbreaking."
He continued: "In my dream world Olly was always going to be my best man and I would have been his. One of the things I wanted most from my wedding day was a photo of him and me together. I'd hoped that on my wedding day he would have been there for me, telling me not to be nervous, giving one of his great Olly speeches. We might have even let him sing!
"I knew things were never going to be the same between us the day he called to tell me he'd got through to the judges' houses stage in September. He announced, 'I'm off to LA'. It was basically hello and goodbye."