Nielsen has reversed a controversial rule changed that was used by NBC to inflate ratings numbers for Heroes.

The double-dip rule effectively allowed NBC to add unduplicated viewer numbers from Saturday's Heroes re-run to the total from Monday's first-run episode, boosting the programme's standing in the weekly ratings ranker and enraging the network's rivals.

In a statement, Nielsen said that it had "received a significant amount of feedback from its clients in which concern was expressed regarding the consequences of this processing change".

Nielsen said that although "NBC's actions were completely consistent" with the ratings measurement firm's reporting policy, it agreed with the feedback and would be "establishing a policy to prevent such a situation from recurring".