A man has been arrested on suspicion of masterminding a £1.6 million cyber raid on cash machines across the country - including some in Sheffield and Doncaster.
The 37-year-old is being held by detectives in Portsmouth after the seven-figure haul went missing from a string of dispensers.
Detectives believe an organised crime gang from eastern Europe inserted a computer virus into cash machines in locations across the country, including some in South Yorkshire.
A suspect was arrested on suspicion of conspiracy to defraud.
Detective Inspector Dave Strange, of City of London Police, said: “An extensive, intelligence-led investigation has uncovered what we believe is an organised crime gang systematically infecting and then clearing cash machines across the UK using specially created malicious software.
“Cyber-enabled crime presents a major threat to our public and private sectors and to an increasing number of citizens.
“The only way to tackle this is by law enforcement and counter fraud agencies working in alliance, which is exactly what the London Regional Fraud Team and National Crime Agency have done over several months culminating in today’s arrest.”
Police said each machine was physically broken into and infected with the software before large amounts of cash were withdrawn.
Nigel Kirby, from the National Crime Agency, said: “The NCA provides specialist support to partners to present a collaborative response to serious and organised crime.
“This operation represents a significant disruption against a sophisticated criminal enterprise who used specialist malware.”