CBB star David McIntosh has hit out at claims that he cheated on Kelly Brook, saying that he is "devastated" by their split. Model Brook ended her engagement to the former Gladiator star last week, confirming the news on Twitter on Friday night by telling her followers: "It's a sad Day but I wanted to share with you that David and I are no longer engaged. I love and respect him and wish him all the best." The announcement came shortly after Sarah Harper, a woman claiming to be McIntosh's ex, told The Sun that the 29-year-old had slept with her while he was dating Kelly. The model has refused to make any further comment on their split but posted several cryptic messages to Instagram, including one that read "Characterize people by their actions and you will never be fooled by their words". McIntosh has now responded to the speculation with an open letter, in which he says his relationship with Harper was purely platonic. "I became friends with Sarah Harper seven years ago but only properly began spending time with her after going through a very traumatic break-up with my son's mother. As well as the stress of the break-up, I had finished working out at sea on stressful, and sometimes dangerous, anti-piracy operations and was drawn to Sarah's happy-go-lucky party spirit. I viewed Sarah as a friend but that was all she was... a friend, nothing more!' "As for Sarah's other claim that I slept with her whilst with Kelly, it is 100 per cent untrue and I categorically deny it. I'm incredibly hurt and sickened by Sarah's false accusations and believe she has done this out of jealousy and spite because she knows that, 1) I'm not interested in her romantically and 2) I only love and want Kelly.I did not cheat on Kelly what so ever! Kelly is my World and, other than my son, she's the only person I've ever truly cared about in my life." He added that he is "absolutely devastated" by Brook's refusal to stand by him following the claims. "Since being with Kelly, I've been so happy. I've been focused and working hard to become the best man I can be. I'm absolutely devastated that Sarah's lies have caused Kelly to end our engagement but am even more deeply upset that the woman I thought loved me and was literally my life my would not stand by me. "In a strange way though, there is a silver lining to all of this because at least now I can breathe a sigh of relief." The full letter is available here.