Bayern Munich goalkeeper Oliver Kahn has advised England captain David Beckham to try and keep his soccer separate from his private life claiming mixing the two is a dangerous cocktail. Real Madrid midfielder Beckham, 29, is one of the most famous footballers in the world with photographers following his every move and newspapers filling columns about his sporting achievements and private life with wife Victoria Beckham -- a former member of the band The Spice Girls."Beckham would be well advised to perhaps think about distancing his private life from his public one," Kahn told SportBild magazine. "Otherwise the sporting performance dips and the person suffers too." German international Kahn, 35, was plastered all over the red-top tabloids in his homeland himself after splitting from his wife but does not have to contend with the amount of media attention afforded to Beckham. Since moving to Madrid two seasons ago Beckham has fought claims that his marriage to Victoria was on the rocks after Rebecca Loos, who acted as Beckham's assistant when he first moved to Madrid, alleged she had a sexual relationship with the footballer. On the pitch Beckham has shown indifferent form for Real and England since his move to Madrid but has vowed to finish his career in the Spanish capital.