Jack Addis, 63, and Jeremy Laxton, 62, both had access to a shared hard drive along with Chief Inspector Richard Watkinson, exchanging large numbers of illegal images over the course of at least three years.
The paedophile ring was uncovered when Laxton came under investigation in Lincoln, leading to the discovery of a series of electronic devices containing indecent images.
On January 12, Watkinson, a Chief Inspector for neighbourhoods policing in the Met’s West Area Command Unit, was found dead as he was on the verge of being charged in the case.
The Crown Prosecution Service had authorised a string of child sex and misconduct allegations to be brought against him.
Addis and Lawton, who have both quit the Met, were charged and appeared at Southwark crown court on Thursday to enter guilty pleas.
According to the charge, the three men conspired to “distribute or show indecent images of children to each other” between January 1 2018 and July 10 2021. The images, which were found on a computer hard drive, included 2,516 in Category A – the worst kind – 1,032 in Category B and 1,701 in Category C.
Laxton, from Grantham, Lincolnshire, also pleaded guilty to three counts of making indecent images of a child, possession of a prohibited image, possessing an extreme pornographic image and possession of cannabis on or before 20 September 2021.
The images include 6,086 in Category A, 4,039 in Category B, 3,597 in Category C, seven prohibited images of a child and 56 extreme pornographic images which were “grossly offensive, disgusting or otherwise of an extreme character” depicting a person having sex with an animal, according to the indictment.
He further admitted a charge of intentionally encouraging or assisting the commission of the offence of misconduct in a public office between December 1 2019 and May 1 2021.
Prosecutor Edward Franklin told an earlier hearing how an investigation into Laxton led to the uncovering of the paedophile ring.
“Police found indecent images of children on various devices”, he said.
“A Met Police investigation discovered more devices and further material including a great number of category A images, still and moving.
“There was then a development where officers found a hard drive – that is the content of the conspiracy charge.
“All three defendants were sharing material with each other.”
He said offences are known to have taken place between 2018 and 2021, but sharing images could have been going on for longer.
More than 13,000 indecent images were found, including some which had been taken by Addis himself.
Addis is already serving an 18-month prison sentence, imposed in December last year in Scotland, for sexual offences against children.
In that case, he admitted photographing a naked 10-year-old boy and recording a 14-year-old boy as he showered, in offences that took place in 2014 and 2015. Addis, who has been married for more than four decades, had a laptop and SD cards in his loft containing more than 20,000 indecent images of children.
It has previously been revealed that the CPS had authorised charges against Watkinson when he was found dead at an address in Princes Risborough, Buckinghamshire. He had been suspended from duty since July 2021.
Met Police Commander Jon Savell previously said: “Chief Inspector Watkinson was facing extremely serious and concerning charges, as the result of a painstaking and thorough police investigation.
“Before this matter came to light, we had no previous information about these allegations or to indicate the officer posed any risk to the public.
“He had not faced any other criminal or conduct matters during his Met career.
“He had been suspended from duty since his arrest.”
At court on Thursday, Judge Tony Baumgartner adjourned sentencing to a date to be fixed and granted Laxton conditional bail ahead of the next hearing on June 23.
The judge said: “A lengthy custodial sentence is inevitable but I will extend bail again to allow him to put his life in order.”
His bail conditions include residence at his home address, to surrender his passport and not to apply for documents to travel outside of England and Wales, that he has no contact with children apart from named family members, and to inform police of any digital devices.
Both defendants left their posts in the Met Police more than a decade ago.
Following the guilty pleas, Commander Savell said: “The content that these men had been viewing has been described by seasoned specialist investigators as some of the most serious that they had ever seen.
“We must never forget that in each video or picture is a real child victim who has suffered unimaginable abuse.
“The effects of child sexual abuse are often traumatic and life-long, and Laxton and Addis both sought sexual gratification from that suffering.
“As a police service we strive to protect the most vulnerable members of society, especially children, and I know officers who served with them will feel utterly betrayed by their disgusting actions.
“We are sickened that they are former colleagues.”