Police believe they have netted an international drug syndicate leader in raids across Melbourne’s north-west this morning.

More than 250 police raided properties across Brimbank, Melton, Wyndham and Hume areas about 7.30am, allegedly smashing one of Victoria’s largest drug cultivation syndicates and discovering cannabis worth more than $29 million.

Indoor farm ... A police officer stands guard over a crop at one of the properties raided today.

The raids were part of a seven-month investigation that unveiled an alleged organised crime syndicate with links to Vietnam.

Acting Superintendent Stephen Mutton said the alleged syndicate leader was one of 12 people arrested today.