A Rugby Football Union disciplinary panel, chaired by Judge Jeff Blackett, on Tuesday night found Moody guilty of punching Leeds' England Under-19 skipper Jordan Crane in an 'A' team game on September 5.
His club Leicester reacted swiftly when they learnt Moody had been cited by Leeds, handing the 27-year-old British Lion a four-week ban after he admitted to striking Crane.
He had only appeared as a second-half substitute against the Tykes, scoring a try in the 53-22 triumph, and it was hoped Leicester's internal action would be taken into account by the RFU.
However, the hearing, convened in Coventry, opted to extend his suspension by a further two weeks.
Moody is available for selection from October 19, freeing him up for Leicester's European Cup opener against Clermont Auvergne and the Autumn Tests against Australia, New Zealand and Samoa at Twickenham.