Three men are facing lengthy jail terms after police swooped on a massive cannabis factory.

Keith Gartshore, 42, Ross Blackshaw, 37, and Christopher Robb, 35, were held in early 2020.

A judge heard how industrial units in Swanston Street in Glasgow's Dalmarnock had been converted for the sophisticated drug-making operation.

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Police seized around £500,000 of cannabis as well as almost £100,000 of dirty money.

The trio today admitted involvement as they appeared in the dock at the High Court in Glasgow.

Gartshore and Robb had also been accused of holding named individuals in "servitude" to work at the units, but not guilty pleas were accepted.

The three had their bail continued and are due to be sentenced in October.

Prosecutor Alan Cameron told the how they were part of a "large scale cannabis cultivation" at several connected industrial units.

He added: "Gartshore, along with others, was involved from May 17 2019 in the setting up of the units."

This initially included sourcing equipment and creating growing areas for cannabis plants.

Mr Cameron: "Over the subsequent months, he visited them obtaining necessary materials such as compost and taking cannabis away to sell."

On December 30 2019, police clocked him drive a van into a car park in East Kilbride.

He handed over a bag to another person in a car - this was later found to contain £53,555 of drug money.

A month later, Gartshore was held by officers. He had a key for one of the units as well as £38,000 of cannabis.

Blackshaw was stopped the same night after police spotted him leaving Gartshore's home in Riddrie, Glasgow.

Blackshaw, of the city's Nitshill, dropped a laundry bag holding £15,200 of cannabis.

Police also seized £22,000 of high-purity cocaine as well as £66, 580 of Ecstasy tablets with another £6,000 of cannabis found in the property.

Detectives then raided the drug factory on February 1 2020.

Mr Cameron said a total of 873 plants were found in the units, which had dozens of lights and fans rigged up.

The prosecutor: "The set up was a professional one with large number of pots containing individual plants."

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The value of the cannabis seized there was more than £450,000 But, Mr Cameron added: "If (all) the recovered drugs were broken down into small quantities and/or further adulterated, the maximum potential values of each would have been higher."

Robb was later caught with £41,685 of drug money in Cambuslang, near Glasgow on April 8 2020.

The trio pleaded guilty to drug supply charges with Gartshore and Robb also admitting to possessing criminal funds.

Lord Scott deferred sentencing for reports.