Reality show Wife Swap won Channel 4 one of its biggest audiences of the year with 6.5 million tuning in to Tuesday night's episode.
Millions shared the experience of Wife Swap's families
The show, in which women switch husbands and families, won 1.5 million more viewers than BBC One's influential
documentary The Secret Policeman.
It was Channel 4's second biggest hit of 2003 - beaten only by the Big Brother 4 final with 7.4 million.
The BBC's expose of racism among police recruits had been heavily publicised.
It has led to a storm of controversy over its undercover reporting - and the resignation of five police officers.
But it did not have the pulling power of Channel 4's real-life family drama in which women spend two weeks away from their partners and children to see if they can cope with a different family.
A Wife Swap spokeswoman said the Channel 4 show had all the ingredients of a TV hit.
"It's just a phenomenal appeal - you are living other people's lives, and seeing just what someone's life can be like for someone else," she said.
Viewers saw Judith Sullivan, of Leyland, near Preston - wife of a disciplinarian civil servant - change character completely when she moved in with easy-going Geoff Millman and his daughters.
Judith, who had not been allowed to socialise without her husband, seemed at first to relax completely - but became more strict when it came to having to impose the house rules.