LORD Peter Mandelson was arrested on suspicion of misconduct in public office today.The former British ambassador the United States was led out of his London home by police officers in the afternoon.He has faced allegations that he leaked market-sensitive information from Downing Street to the paedophile financier Jeffrey Epstein.A spokesperson for the Metropolitan Police said: “Officers have arrested a 72-year-old man on suspicion of misconduct in public office.