A drug supplier who is linked to the deaths of at least two people from hugely powerful Class A nitazene drugs has admitted a raft of criminal charges, following a National Crime Agency investigation.

Polish national Robert Poleszak, 45, had already admitted supplying cocaine and nitazenes – which are around 1,000 times more powerful than morphine – when he appeared at Reading Crown Court on yesterday [28 May].

Poleszak further admitted making 5,134 Category A indecent images of children – the most severe – possession of extreme pornographic images and 20 drugs charges including conspiracy to supply cocaine, crack cocaine and methylamphetamine.

Poleszak, of Elgar Road, Reading, also admitted conspiring to supply nitazenes, which are a synthetic opioid and have been linked to more than 1,000 drugs deaths in the United Kingdom since June 2023.

Nitazenes are manufactured in labs in places like China and smuggled to the UK by abusing fast parcel, post and Royal Mail Services. Because of their potency, often only tiny amounts of nitazenes are needed by crime groups to produce strong street drugs.

Poleszak operated on the dark web, where he advertised a variety of substances, including Oxycodone, which is normally prescribed to manage pain. Poleszak offered up to 200 Oxycodone pills per transaction, but they also contained Isotonitazene.

NCA investigators established that Poleszak made more than 100 sales of Oxycodone.

Numerous reviews had been left for him, stating that many customers had overdosed and ended up in hospital, and that the drugs contained nitazenes.

NCA officers identified Poleszak – who also used the alias Krzysztof Wozniak – and traced him posting packages to customers from a Post Office in Broad Street, Reading.

He was arrested on 1 October 2025, and officers searched his home.

Inside they found a drugs lab and evidence of his offending: snap bags, scales, powders, pill dyes, face masks and filters. A video on Poleszak’s mobile phone showed him constructing a pill press.

Poleszak’s criminality was linked to the death of a drug user in Cornwall in February 2025. Evidence suggested Poleszak supplied Isotonitazene pills to a local drug dealer who sold them to a drug user who died a few days later.

In May another user in Henley-on-Thames, Oxfordshire, died. Nineteen green nitazene pills were found in their bedroom along with packaging, an envelope and address labels identical to those found in Poleszak’s home. Poleszak’s finger prints were also found on the envelope.

Tim Lambert, NCA Senior Investigating Officer, said: “Offenders don’t really get much lower than Robert Poleszak who had thousands of child sexual abuse images and happily supplied a drug known for killing people.

“Tackling Class A drugs, including synthetic opioids, is a priority for the NCA to stop the harm they cause to users, communities and the UK economy.

“We’re working closely with policing, Border Force and international partners to stem supply of nitazenes and other synthetic opioids to and within the UK.”

Poleszak is due to be sentenced on 17 July 2026.