Nine defendants appeared today before Sheffield Crown Court following an inquiry by the Yorkshire and Humber Regional Organised Crime Unit.
Supported by South Yorkshire Police officers in Doncaster, they uncovered a catalogue of criminal offending across the Yorkshire and Humber region.
In total, eight defendants entered guilty pleas to conspiracy to supply Class A drugs, namely heroin. Their names and sentences are:
Tommy Lee Smith, 38, of Stockbridge Lane, Bentley '“ sentenced to 12 years in prison
Stacey Jane Bowman, 37, of Hennessey Court, Thorne '“ sentenced to six years in prison
Jack Daniel Pye, 27, of Coronation Road, Stainforth '“ sentenced to four years in prison
Lee Thomas Hodgkinson, 41, of Ingham Road, Dunscroft '“ sentenced to two years and eight months in prison
Yogi Winsper, 22, of Blackpool, Lancashire '“ sentenced to two years and eight months in prison
Jonathan James McAvoy, 38, of Station Road, Dunscroft '“ sentenced to five years in prison, which includes a two-year jail term for a burglary offence
Michael Scholey, 42, of Station Road, Stainforth '“ given a two-year suspended sentence
Jacqueline Joan Williams, 39, of Station Road, Stainforth '“ given a two-year suspended sentence
Smith also received a Serious Crime Prevention Order.
A ninth defendant, 40-year-old Jonathan Stray, of Lakeen Road, Doncaster, pleaded guilty to conspiracy to supply cannabis. He received a two-year jail term today.
Paul Derek Pannett, 20, of Brigg, North Lincolnshire, also pleaded guilty to conspiracy to supply Class A drugs and will be sentenced at a later date.
The unit launched their inquiry, codenamed Operation Railbird, in December 2015 after South Yorkshire Police reported concerns about a travelling group who were committing offences in the region including cash machine thefts, drug supply, robberies and firearms incidents.
In the months prior to Operation Railbird being launched, police said the behaviour of the group was becoming '˜increasingly problematic', with incidents of overt violence, damage to commercial and residential property, knife attacks and firearms discharges were being reported all over the region.
Detective Inspector Lee Fletcher, from the Yorkshire and HumberÂ Organised Crime Unit, said: 'This has been a complex and significant inquiry into a violent and unpredictable organised crime group, who operated through fear and notoriety, believing they were untouchable.
'The behaviour of this group was incredibly dangerous and linked to feuding with a rival gang, but the escalation of violence experienced in late 2015 posed a significant risk for serious harm and even death within local communities.'
Over the course of the investigation, the unitÂ dismantled five safe houses and recovered four hydraulic presses used in the supply of Class A drugs.
They seized multiple kilogrammes of heroin, two kilogrammes of cannabis, one kilogram of amphetamine and 30 kilogrammes of cutting agents as well as around 100 bladed weapons including machetes,Â one Uzi-style machine gun, two revolvers, two semi-automatic guns and ammunition.
Many of these weapons were recovered from the travellers' site in Bentley, Doncaster and policeÂ seized around Â£115,000 in cash from another travelling site in Armthorpe, Doncaster.
DI Fletcher added: 'As a result of our proactive and targeted policing, hundreds of dangerous weapons are now off the streets and an organised criminal gang is behind bars. We will continue to work alongside forces across the region to disrupt and dismantle any criminal groups who are causing harm to our communities.'