Cannabis grow houses in Victoria are increasingly state-of-the-art. The plants are identical, quick growing and filled with the potent chemical THC with police saying the best syndicates have perfected their hydroponic systems. "Put it this way," one detective said, "If they were growing tomatoes for the supermarket you would buy them." According to Assistant Commissioner (Crime) Steve Fontana: "Melbourne is the engine room of the country's cannabis industry." The size is staggering. On available figures (excluding wastage and failed crops) the wholesale market is worth $1.5 billion and the retail well over $8 billion, making it one of the state's biggest businesses. Years ago if police found a crop house they would place it under surveillance in the hope of catching the king pins with the drugs. A lengthy prosecution, a conviction and probable jail sentence of a few years might follow.

Corrupt sparkies build giant power boards for grow houses that can divert (and steal) about $1000 of electricity a day. Even though it is a lucrative organised crime racket, courts seem to treat cannabis as a so-called soft drug. After all, many of the judges may have smoked the odd joint when they were at university. "The cannabis produced today is far more potent than ever before," says the head of the Drug Taskforce, Detective Inspector Phil Harrison. Assistant Commissioner Stephen Fontana says police are embarrassed by the mishandling of evidence. Credit:Joe Armao Police say the grow house industry pump primes many other arms of organised crime with much of the profits re-invested in producing local speed and importing Chinese manufactured ice, South American cocaine and Asian heroin.

The reality is the industry is now too vast for traditional policing. If all the hydroponic gear and cannabis was stored as evidence it would cost a fortune in warehouse space and create major health and safety problems. Grow houses are all dangerous fire traps, powered by massive power boards not designed for industrial style electricity demands. And so police changed tactics embarking on a guerrilla war against the syndicates using a hit and run style to disrupt and destroy. With an estimated 1500 grow houses operating across the state police don't have the resources to run full investigations on every one. Instead of building a brief of evidence in every case, increasingly the tactic is to chase the profits. An estimated 1500 grow houses operate across Victoria.

Acting on tips from police, members of the public, real estate agents, neighbours and power companies, detectives from the Drug Taskforce are hitting crop houses at a record rate. As part of Operation Chronos they raid properties, arrest crop sitters (mostly the houses are left vacant) and seize the plants. Forensic experts confirm the plants are marijuana and the crop is then destroyed. Many drug syndicates make their properties look a little less like run down rentals and more like the house next door. Asset experts from the Criminal Proceeds Squad are called in to try to track the real renters then identity any property or other assets that can be seized from bank accounts to luxury cars. And while many try to bury the profits in the names of relatives, police, with the help of the Australian Criminal Intelligence Commission, are following the financial thread.

When police raid a crop house it is declared unfit for human habitation, which means innocent owners of rental properties are forced to pay huge amounts to repair and restore their investments. The result? In little more than three months police have raided 77 crop houses, made 28 arrests, frozen seven houses and seized more than 10,000 plants weighing well over four tonnes that has a wholesale value of $25 million. To make it clear that is what the growers get. It is worth a truckload more if the final dried product was allowed to hit the street (about $100 million if sold at $20 a gram). "We are determined to break the back of this industry," says Fontana. Police say the best syndicates have perfected their hydroponic systems. He says for years Victoria had one of the lowest number of seizures but the highest weight seized – indicating the crops were the biggest in the country.

The syndicates make their properties look a little less like run down rentals and more like the house next door, sprucing up the front garden. "Some look like your grandmother might live there," says Harrison. Acting on tips from police, members of the public, real estate agents, neighbours and power companies, detectives from the Drug Taskforce are hitting crop houses at a record rate. One brick veneer looks well kept – the lawns are mown, the garden weeded and there is even a ladder on the side, making it look like a run-of-the-mill family residence. On entering there is a nice colonial-style kitchen, a wall-mounted flat-screen, and a comfortable leather couch. Walk further and you see up to 100 bags of fertiliser and room after room of crops, from seedlings to mature plants with giant heads. While the houses don't draw immediate attention most won't pass the sniff test. "It is the responsibility of real estate agents to check rental properties. The smell from these grow houses is horrendous. You can smell it at the front door," says Harrison.

In the last few days we accompanied Drug Taskforce detectives and regional police on three raids in Narre Warren. One property was a lovely double-storey number with a lock up garage that looked like every other house in the street. Inside was an Albanian crop worth a fortune. About five streets away was another crop in a smaller house – this time run by Vietnamese judging by the look of the startled crop sitter found hiding inside. This house was less than 200 metres from a local primary school and it is a fair bet parents would walk their children past it ever day unaware inside were about 100 cannabis plants at different levels of maturity. When police raid a crop house it is declared unfit for human habitation, which means innocent owners of rental properties are forced to pay huge amounts to repair and restore their investments. And they are all dangerous fire traps, powered by massive power boards not designed for industrial style electricity demands (in one year more than 40 major domestic fires turned out to be crop houses). "We will not allow our members into these premises until the power has been disconnected," says Fontana. In one recent raid police found nine sections from nursery to growing, drying rooms and 480 plants potentially worth $1.2 million.

In another, a disused factory, police found 1900 plants with a value of $4.7 million. There was a forklift left outside to make it look as if it was legit. In the dope business there are corner stores and giant businesses. There are one-off crop houses run by single families and syndicates that run up to 30 properties at a time. Some growers have armed themselves, built elaborate traps and fortified their buildings to deter fellow criminals from "run throughs" (bandits who burst in to steal the dope). Police say several murders were committed in crop houses. And if an unregistered international student who works as a crop sitter goes missing, who would know? The big syndicates use production line methods. With different lights and nutrients in designated rooms the plants are moved as they grow and fed by automatic timers. The harvested crop is dried, packed and then vacuum sealed. Some corrupt real estate agents find properties for growers while others have tipped off police to their suspicions that the renters are fronts for major syndicates.

Clearly some are using bent plumbers and electricians (police say many of the power boards are purpose built). And some crooks have bought run down properties to use as crop houses only to sell them later for a profit (a risky proposal as they can lose the lot if asset police come calling). There is one group that refuses to help – hydroponic retailers, with not one snippet coming out of that industry. Surely when someone comes in and orders enough hydroponic lights to heat Greenland the seller must know the buyer is not trying to grow the Best Orchid for the Royal Melbourne Show. Increasingly the big syndicates are heading to the country (well the government has urged industries to think regional) reasoning there are less cops to sniff out your crops. But they haven't factored the community spirit in country towns and so when a group of Albanians walk into the local pub, ignore the Pot and Parma special and order Tave kosi (baked lamb with rice) and a glass of Rakia they will be the subject to some local interest. "We have found local communities have been quick to report unusual movements," says Fontana.