More animal welfare charges have been laid over the alleged mistreatment of bobby calves in Waikato.

The Ministry for Primary Industries (MPI) launched a probe last September after secret video footage revealed animals being severely mistreated on a farm and in a slaughterhouse.

The footage showed calves been torn from their mothers and left in the hot sun for hours. Bobby calves were also thrown into trucks and beaten to death, and kicked and thrown about at a slaughterhouse.

MPI said today it had laid a second set of charges in relation to the alleged offending.

Four representative charges — laid against a company and an individual — have been filed in the Huntly District Court under the Animal Welfare Act and the Animal Products Act. A hearing on the charges has been set down for June 21.

It comes after 10 charges were laid against a separate individual in March. The next appearance on those charges will be on June 2.

MPI’s ongoing investigation has involved reviewing “many hours of footage” of the alleged offences.

Acting compliance director Steve Gilbert said the investigation has been careful and methodical, and investigators were actively pursuing other lines of inquiry.