Margaret River resident Marcus John Spiers, 45, of Fantail Place, received a 20 months jail term after he appeared in Bunbury District Court on November 9.

He was convicted of cultivating and possessing cannabis with the intent to sell and supply.

Detectives found 380 mature cannabis plants at his home and more than 3kg of cannabis.

Busselton resident Daniel James McAuliffe, 30, of Country Road, received a three-year jail term after he was convicted for possessing 26kg of cannabis with the intent to sell and supply.

Detectives estimated that the cannabis was worth between $350,000 and $400,000.

The men were charged in phase three of the Tall Timbers operation, when five search warrants were executed in Margaret River, Cowaramup and Busselton resulting in almost 30kg of cannabis and more than 800 cannabis plants seized.

Busselton Det Sgt Paul Ford, who headed the Tall Timbers operation, said that 20 people were charged in the operation, which resulted in the seizure of drugs and assets to the value of $16m.