Image copyright National Crime Agency Image caption Clockwise from top left: John Denham, Matthew Stansfield, Adam Toms, Matthew Lisk, Robin Hollyson, Christopher Knight and David Harsley

Seven paedophiles who preyed on a baby and young children acted "beyond human instinct" and were guilty of "terrifying depravity", a judge said.

Jailing them, Judge Julian Lambert said the men had engaged in "the most grossly deviant behaviour imaginable".

He said what they had done made some feel "physically sick".

The prison sentences issued to the gang members, who streamed some attacks on the internet, range from two years to 24 years.

The court was told the men would drive hundreds of miles for a chance to rape or abuse a child.

In the worst nightmare, from the very deepest recesses of the mind, at the darkest hour of the night, few can have imagined the terrifying depravity which you men admit Judge Julian Lambert

The group, who lived at addresses across England, raped and assaulted three children - a baby, a toddler and a young child - between 2013 and 2014.

Bristol Crown Court heard the men groomed families to get to children, in one case targeting a pregnant woman in order to abuse her baby after its birth.

They would stream and watch attacks live online, providing encouragement to those carrying out abuse. They also shared advice over online chat logs about how to drug young victims.

The judge said: "In the worst nightmare, from the very deepest recesses of the mind, at the darkest hour of the night, few can have imagined the terrifying depravity which you men admit."

He said the depths they sank to were "shocking to all decent people", "provokes tears in many and makes others feel physically sick".

Media playback is unsupported on your device Media caption Andy Quinn, from the National Crime Agency, said the crimes were horrific

"What you did is contrary to all nature and humanity and you each appear to have a chilling tendency to centre the world on yourselves and your depraved desires without regard for the innocent and vulnerable."

John Brown, from the the NSPCC, said the gravity of the offending is "difficult to comprehend" and the children involved may be affected in later life.

He said: "It may be that they don't have a recollection of what's happened, but trauma can manifest itself in later years so I think that's really important to watch out for.

"Those babies and those children are going to need to be monitored and they need to have on-going longer-term support, and their families as well."

The inquiry began in September 2014 when defendant Adam Toms dialled 999 and was heard crying down the line.

He was arrested after officers were sent to his home following concerns for his welfare and he admitted sexually abusing a child under the age of five.

This triggered the uncovering of an organised crime group, and the resulting inquiry was led by the National Crime Agency (NCA).

Robin Hollyson, 31, from Bedfordshire, was sentenced to 24 years in prison and a further eight years on licence. He was filmed abusing the baby.

Christopher Knight, 35, from Manchester, was jailed for 18 years, with an extension of six years on licence

Matthew Stansfield, 35, from Hampshire was jailed for 14 years

Adam Toms, 33, from Somerset, received a 12-year sentence, and four years on licence

John Denham, 50, from Wiltshire - previously known as Benjamin Harrop - was jailed for eight years plus four years on licence

Matthew Lisk, 32, from East Sussex, was jailed for four years, plus an extension of three years on licence

David Harsley, 51, from East Yorkshire, was jailed for two years

All were placed on the sex offenders register for life, except for Harsley. The judge has yet to determine how long he will be on the register for.

Media playback is unsupported on your device Media caption Matthew Stansfield refused to comment to police when arrested

Ian Glover, who headed up the National Crime Agency investigation, described them as "by far the worst paedophile group I have ever investigated".

He said they had treated children "as a commodity, to be passed on to others, to be filmed, to be abused and that abuse shown to other paedophiles as a form of currency, so they can get other material back".

Mr Glover said the most important factor had been protecting the children involved, both in this court case and the wider operation, and as a result more than 200 "packages" - intelligence gathered during the inquiry - had been sent to other forces, mostly overseas. Further convictions are expected in the UK and abroad, he said.

The investigation identified three victims but police have put measures in place to protect another 21 children found to be at risk.

Det Ch Insp Simon Crisp, from Avon and Somerset Constabulary, said: "The extremity of the offending in this case is horrifying, but child abuse of this nature is rare."