People planning to buy or sell drugs online undetected had better think again, WA Police have warned, after three people were convicted for buying drugs off notorious marketplace website, the Silk Road.

Two brothers, aged 15 and 17 years old at the time of arrest, were jailed last month for buying drugs online as part of Operation Cinder, run by Esperance detectives and technology crime investigations last year.

The pair were charged with 16 drug related offences, including possession of a prohibited drug with intent to sell/supply and attempt possession of drugs with intent to sell/supply after using the Silk Road website to buy drugs.

The 17-year-old was sentenced to 12 months' jail, while his 15 year-old brother was jailed for 8 months.

A marketplace like eBay, transactions on Silk Road are encrypted, anonymous and made using the online currency Bitcoin, however technology crime investigation manage Detective Senior Sergeant Douglas said WA Police were aware of online drug purchases via Silk Road,