One of Britain’s most wanted fugitives has been arrested in Madrid over alleged sexual assaults carried out over a decade.

John Rocks, 37, was detained by the Spanish National Police on Saturday, following an investigation launched by police in Scotland in 2024.

The National Police said he had been concealing his identity and living a “nomadic life”.

In a statement, the force said: “The investigation began in 2024 after police in the UK reported several sexual assaults committed between 2012 and 2022.”

An international warrant had been issued for his arrest in February, and the National Crime Agency (NCA) has thanked Spain’s police for their “excellent work” in detaining him.

Police had initially searched for Rocks in the Alicante town of Benidorm, before further evidence led them to Madrid.

The force said a surveillance operation was set up on a central street in Spain’s capital.

It added: “The actions taken to locate the target included several trips to Benidorm, as well as numerous surveillance operations and on-site checks at places he frequented.

“These efforts allowed investigators to establish patterns of behaviour, obtain clues about his possible location, and identify third parties who might be assisting him. The investigation proved particularly complex due to the concealment measures taken by the wanted man.

“During the operation, the target, who was wearing a cap and glasses to partially conceal his face, was located and arrested.”

He is now being held in a Spanish prison pending a decision on his extradition, police said.

Rick Jones, NCA’s Deputy Director International, said: “This arrest marks the 101st arrest in Operation Captura, a multi-agency campaign aimed at tracking down the UK’s most wanted individuals in Spain.

“I pay tribute to the excellent work of our colleagues in the Spanish National Police who made this possible. Working with them, and other law enforcement partners we are determined to do all we can to ensure fugitives are returned to face the courts.”

Rocks was included in a publicity campaign for the UK's most wanted fugitives, promoted by the National Crime Agency (NCA) and CrimeStoppers, which the Spanish Ministry of the Interior joined in May.

The appeal was launched to locate 12 of the UK’s most wanted fugitives, who were believed to linked or hiding in Spain.

It formed part of the agency’s Operation Captura, which has seen dozens of fugitives apprehended.