The rumour is, and Ricky himself hinted at it on the show, it was because he found out that for years his dad was secretly taking a cut of the fight money for himself, Hatton's dad was his manager for years. Hatton only eventually found out because people like Billy Graham and others involved in his team complained about their pay and he did some digging, it was his dad Ray short-changing them all and keeping some of money that should have been spread around.
Also read in his book where he said how his parents used to blank him, his missus and their kids for months on end and they've also put a lot of stuff in the papers over the last year or two about him being a drug-addict and an alcoholic. All this, as well as the money story if it's true which it probably is, is why he doesn't speak to them and I don't blame him personally.
