Police have busted a large-scale cannabis growing operation at two houses in the posh Auckland suburb of Orakei.

One police home seen this morning is valued at $3.12 million by the council. The other was valued at $2.52 million.

The garage of one of the houses was filled with a meter-long pile of cannabis plants. Police were putting the plants in a truck waiting in the driveway.

At another address, employees dismantled and removed air ducts and air filters, as well as lighting fixtures, electric fans and reflective materials.