WA Police have warned Midland motorbike sellers to be cautious when selling on online market places following a spate of high value motorbike thefts in recent weeks.

Thieves are going through online ads pretending to be interested in purchasing motorbikes to obtain addresses and later turning up to steal them.

A police spokesperson said it is increasingly common for criminals to target high-value items this way, and have warned sellers to be vigilant.

WA police have recommended that when people post online ads they do not identify an address and consider a safe public place with good lighting and CCTV to meet with any potential buyers.