The 35-year-old Britain's Got Talent judge and former So Solid Crew star Harvey, also 35, split when his affair with Javine Hylton was exposed.
READ: ALESHA DIXON ON EX HARVEY'S AFFAIR WITH JAVINE – "I CONSIDERED SUICIDE"
Last month, Alesha's tell-all interview with Piers Morgan was screened, and Harvey allegedly was not happy when he found out she would be taking part.
According to insiders Harvey wanted to get a gagging order to prevent Alesha talking about him on the show but, when she got her legal team involved, he realised he didn't have a leg to stand on.
A source told The Sun: "When Harvey found out Alesha was going on Life Stories, alarm bells started ringing. He can be a hothead and immediately fired off an angry text, warning her not to slag him off.
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"He apparently said he could take some action to ban her from talking about him. Alesha is a tough girl but the tone of the message was so rude it really upset her.
"Rather than get in a slanging match, she passed it to her lawyers and let them deal with it. They contacted Harvey and told him to back off.
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"Alesha always remained a dignified throughout the ordeal. But when you are doing a show called Life Stories a marriage and divorce has to be discussed."
She and Harvey married in 2005, after meeting in 2000, but split a year later when his affair was uncovered.
Now in a relationship with Azuka Ononye, Alesha gave birth to her first child, daughter Azura Sienna, last year.