TOP-SELLING novelist John Grisham says people who look at child pornography "probably had too much to drink" and should be given lighter prison sentences.

Grisham, 59, criticised the length of imprisonment imposed on offenders who download images of children being sexually abused.

He revealed one of his "good buddies" had been caught in a child porn sting. His comments came in an interview in which he blasted the American justice system and high number of serving convicts.

"We have prisons now filled with guys my age. Sixty-year-old white men in prison who've never harmed anybody, would never touch a child," he said."But they got online one night and started surfing around, probably had too much to drink or whatever, and pushed the wrong buttons, went too far and got into child porn."

He added "too many people" are locked up for minor drugs charges, child porn offences and white collar crime. The author of legal thrillers has sold 275 million books.

His friend from law school was jailed for three years for viewing child porn on a site claiming girls were 16. Viewing child porn fuels abuse of youngsters but Grisham said sentences should be lower for people downloading content.