Boris Becker has shed a stone in prison. The German tennis legend was jailed for two and a half years in April for fraudulently hiding £2.5 million in assets to avoid paying debts but his lawyer claims that he is thriving at HMP Huntercombe in Oxfordshire by teaching fellow inmates to keep fit. Becker’s lawyer Oliver Moser told German media: “Our client Boris Becker is still doing well given the circumstances and he fits constructively into everyday prison life.” The 54-year-old sports star is said to have his own private cell and his behaviour in prison has been described as impeccable. A clo…