Two more large companies have pulled out of sponsoring a Northland rodeo because of concerns of animal mistreatment.

Photo: RNZ / YouTube

Checkpoint with John Campbell revealed footage on Monday of the Mid Northern Rodeo that appeared to show calves being electric-shocked, which is against government regulations, as well as animals in states of distress.

A Ministry for Primary Industries (MPI) investigation into the allegations is under way.

Yesterday, real estate companies LJ Hooker, Harcourts and Ray White all cancelled their sponsorship of the rodeo.

Today they were joined by building supplies company PlaceMakers and concrete supplier Firth.

In a written statement, PlaceMakers said the company was "heavily involved" in communities and supporting local events.

"However, we will be withdrawing our support and future involvement in this event."

Firth said its staff were being advised not to support rodeo events in the future.

Neither company commented on the MPI investigation or the footage.