Members of an organised crime group, who were setting up a drug laboratory in the garage of a house in Woodvale Road, Radcliffe, were unaware officers watched their every move.

Head of the crime group, Neil Strong, aged 32, who is originally from Prestwich but had been orchestrating the plot from his luxury Spanish villa in Alicante, was sentenced to four years at Manchester Crown Court last week for conspiracy to supply amphetamine.

Strong and his three criminal associates - Damian Vose, aged 38, of Woodvale Road, Radcliffe; Paul Cuthbert, aged 45, of Harris Drive, Bury; and Daniel Pinder, aged 33, of Beechdale Close, Manchester – all pleaded guilty. Vose was sentenced to 32 months; Cuthbert and Pinder received 30 months each for their roles in the conspiracy.

The men had purchased barrels of dangerous chemicals, including sulphuric acid and methanol, to produce pure amphetamine paste.

Steve Baldwin, NCA Regional Head of Investigations, said: “The crime group had no idea they were under surveillance. When the time was right we made our move and stopped them in their tracks. I have no doubt they would have gone on to flood the streets with amphetamine.

“Drugs destroy communities and these men had no regard for the misery and damage they would have caused. Our investigation does not stop here though as we are now working with our partners, both here and in Spain, to strip them of their criminal assets.”

When officers raided the laboratory at Vose’s house in August 2013, Strong, who had flown in to oversee the production process, and two of the crime group members were about to start making their first batch of amphetamine worth £1.6million.

Strong tried to evade arrest by jumping over a fence but failed. Cuthbert was found hiding in the undergrowth, while Vose was arrested inside his house. Officers had arrested Pinder two months earlier.

Chemicals, an electric mixer, scales, a 10-ton press, a vacuum packing machine and other drugs paraphernalia were recovered. More presses were found at stables owned by Strong at Nutt Lane in Prestwich, while containers full of the chemicals were seized at his Spanish villa.

Assets including properties and a yacht belonging to Strong have been restrained as part of the financial investigation. A confiscation hearing will now take place.

Officers have received assistance from the Spanish National Police, Greater Manchester Police and Cheshire Police throughout the investigation.