Radio shock jock Alan Jones, along with broadcasters 2GB and 4BC, have been ordered to pay $3.75 million after being found guilty of defaming a Queensland family.

Brothers Denis, John, Neill and Joe Wagner sued Jones to the tune of $4.8 million for suggesting they were responsible for the deaths of 12 people during the 2011 Grantham floods due to a wall of a quarry they owned collapsing during the natural disaster.

The Wagner brothers claimed Jones made the accusations across 32 different broadcasts on stations 2GB and 4BC, as well as once on Sky News, during 2014 and 2015.

The judge-only trial lasted seven weeks, with Justice Peter Flanagan finding that Jones and 2GB were guilty of conveying “extremely serious” defamatory allegations against the Wagner brothers in 27 of those broadcasts.

Journalist Nicholas Cater was also facing a defamation lawsuit, but the claims against him were dismissed.

During the trial, Jones admitted his on-air comments about the Wagner brothers were “savage”, while the radio shock jock’s barrister conceded that some of his comments were “unable to be defended”.