Serving prisoners and petty criminals are to be sentenced for their part in a "sophisticated" operation to supply and fly drugs into jails using drones.

In all, the criminal gang was responsible for 49 drone drops and four throw-overs of contraband including mainly psychoactive substances with a total prison value of up to £370,000.

Members of the group face sentence at Birmingham Crown Court over two days, after making admissions or having been convicted of their roles.

READ MORE: Police snared 'most sophisticated' organised crime gang in drugs raid

Prosecutors said the "commercial operation" ran for two years, from mid-2015, in which "mainly" drugs, but also tools, phones and even a TV Freeview box, were delivered to order.

Remote-controlled drones, equipped with a fishing line and hooks, were flown to cell windows where inmates - in contact with the pilot - used tools such as an extendable broom handle to retrieve the goods.

Jail CCTV showed other prisoners then visiting the cells and walking out with packages, believed to be their illicit orders.

Of the drone flights, 34 evaded security and got through and the true total value of the goods is therefore unknown.

On the outside, payment was taken for contraband through the accounts of "leading" player and serving prisoner Craig Hickinbottom's girlfriend.

Police found references to cash sums in accounts linked to Hickinbottom's 32-year-old partner Lisa Hodgetts, from Tividale, West Midlands. She admitted money laundering.

Evidence showed records of different prisoners' orders were kept by using the pennies column of each individual payment as a reference to a prison inmate's cell number - for example "37p", in reference to cell 37.

READ MORE: Police snared 'most sophisticated' organised crime gang in drugs raid

Hickinbottom, 35, who was a prisoner at HMP Featherstone in Staffordshire, and later HMP Hewell in Worcestershire, organised deliveries to both jails during the conspiracy.

He admitted four counts of conspiring to bring contraband into prison, and conspiracy to supply psychoactive substances.

Opening the Crown's case on Tuesday, Michelle Heeley QC said: "The case involved an agreement to bring items into prison, initially this was done by throwing packages over.

"Thereafter the agreement became more sophisticated and the group used gangs to fly drones in."

She added: "The Crown accepts there may well have been others using drones, but rely only on the evidence in this case that can attribute these specific drone flights to this criminal gang."

Drone pilot Mervyn Foster, of High Street, Tipton, West Midlands, was described by the prosecution as the conspiracy's "prime organiser on the outside", and Hickinbottom's "counterpart".

The 36-year-old, who was a petty criminal with 31 convictions for 76 offences, worked with "right-hand man" John Quinn, 35, of Swancroft Road, Tipton.

Quinn admitted three counts of conspiracy and another of conspiring to supply psychoactive substances.

Foster had others assist with packaging and transport: Terry Leach, 19, of Wednesbury Oak Road, Tipton; Ashley Rollinson, 21, of Waiver Road, Brierley Hill; Yvonne Hay, 41, and her boyfriend Francis Ward, both of Bloxwich Road, Walsall.

All four will be sentenced for their roles in the conspiracy.

READ MORE: Police snared 'most sophisticated' organised crime gang in drugs raid

Foster obtained some of the drugs he sent in from 30-year-old Artaf Hussain, of Slater Road, Tipton, who pleaded guilty to being concerned with the supply of cocaine.

On the inside, Craig Hickinbottom was assisted with distribution in jail by cousin and co-conspirator John Hickinbottom, 50, who acted as "warehouse man", his barrister said, and was paid in heroin.

Hickinbottom's cellmate Sanjay Patel, 37, of Telford, Shropshire, but formerly of Cheltenham in Gloucestershire, used one of the illegal mobile phones which had been flown in - an offence he has admitted.

The operation, from July 2015 until May of this year, included throw-overs at HMP Stoke Heath, Shropshire, and Hewell.

Prosecutors said "almost daily flights" were recorded to jails including Hewell and Featherstone, but there were also trips to HMP Birmingham, HMP Doncaster, HMP Lindholme in Yorkshire, HMP Risley in Cheshire, HMP Liverpool, and as far north as HMP Perth in Scotland.

Sentencing concludes on Wednesday.