RAIDS that uncovered secret cannabis growing operations inside St Helens homes proved crucial to a covert police probe that led to nine members of a Chinese drug gang being jailed.

The discoveries of the skunk cannabis factories hidden inside houses at The Clubhouse, in Haydock and on Prescot Road in March last year gave detectives key breakthroughs in the major investigation, the Star can reveal.

More than 1,000 plants were found in the homes - and a number of Chinese men involved in growing the drugs were sentenced earlier this year.

But they were small players in the drugs plot compared to the nine suppliers put behind bars with combined sentences totalling almost 30 years following a Liverpool Crown Court case.

The gang – made up mainly of illegal Chinese immigrants were members of one of the country's largest ever cannabis growing rings, say police.

The cultivated skunk cannabis – reported to have a street value of at least £21.2 million - was in at least 33 rented houses across the region.

On the outside these appeared to be respectable homes. But reams of plants and hydroponics equipment were found in the St Helens houses – and the set ups left property owners with massive repair bills.

Detective Inspector Earle Garner, from Merseyside Police’s Matrix unit, said information gleamed from the operations in St Helens gave them a “significant breakthrough” that led police to key gang members 49-year-old Yu Wu and Da Yong Jin, 42.

Judge David Harris sentenced Yong Jin, of Knight Street, Liverpool, to five years and seven months.

Wu, also of Knight Street, helped set up the houses, and was sentenced to four years two months following a guilty plea.

The most senior figure in the network to be jailed was Yan Yan Li, a woman who DI Garner described as being at the “top of the tree” in Britain’s illegal drug network.

The 29-year-old, of Greenheys Street West, Hulme, Manchester, was jailed for six years eight months.

Other gang members, who played a variety of roles, received sentences ranging from five years to 14 months.

DI Garner added: “This operation has certainly led to a reduction across Merseyside in cannabis production, though it hasn’t stopped it.

“There people were involved in a complex conspiracy and in terms of cannabis production it was the biggest in Merseyside.

“The St Helens raids were a significant part of the investigation, in particular those at The Clubhouse, in Haydock and the Prescot Road gave us links to other addresses that helped our progress.”