A pair of cannabis farmers have been told to expect long jail sentences after they were found growing 222 plants at a smallholding in Holsworthy.

Landowner Paul Hensher and former company director Aleck Robbins ran their operation on a continuous cycle so that around 60 plants were ready for cropping every few weeks.

They kept meticulous notes about the progress of each batch as it neared maturity in their high tech hydroponic set up, which was capable of producing up to £180,000 of drugs a year.

They sold their crop for £170 an ounce to a network of local users, who told them they used it to for medicinal use, Exeter Crown Court was told.

Hensher, aged 63, of Parnacott Farm, and Robbins, aged 57, of Holsworthy, admitted production of cannabis and will be sentenced next month.

A dispute about their role in the operation and whether it was being run on a commercial scale was resolved after Judge Timothy Rose agreed they fell on the border between a leading and a significant role.

They claim they were building up the capacity of the cannabis farm in the hope that the drug would be legalised and licensed for medical use in the near future.

The judge adjourned sentence to enable the men to prepare for their sentences and for their defence teams to obtain personal references and reports on their health.

The judge said: "This was a commercial enterprise even if they were selling to people they knew and who were adults.

"This was a dedicated and truly substantial arrangement in numerous rooms with a great deal of equipment.

"It is a significant piece of criminality. There is not going to be any other outcome other than custodial sentences of some length. It is inevitable that they are both going to prison."

Rob Yates, prosecuting, told a previous hearing it was a commercial operation in which both men played a leading role. The plants had the potential to produce drugs worth between £62,000 and £180,000.

Rupert Taylor, for Robbins, said the crop was sold at £170 an ounce to a small number of contacts who they believed were using it for medicinal purposes.

Christopher Spencer, for Hensher, said: "They were not aware of the scale of what they started. There is no evidence they had any contacts which would enable them to dispose of these amounts."