UK police have arrested three men suspected of being involved in thousands of phishing attacks on banking customers.

One Nigerian and two Romanian men were arrested at a central London hotel on Monday evening on conspiracy to defraud and money laundering charges. The men were taken to a central London police station for questioning.

The three men were allegedly involved in an operation that placed over 2,000 phishing pages on the internet, the Met Police said in a statement on Tuesday.

The phishing pages mimicked banking sites, and were designed to harvest credentials from unsuspecting users, said the police. Fraudsters then illegally accessed the accounts and stole money.

Police have seized computers for forensic examination, and searches are continuing in London and in the Midlands, said the statement.

The arrests were made as part of a joint operation between the Metropolitan Police Central e-Crime Unit (PCeU) and the Serious Organised Crime Agency (SOCA) cyber unit. The two units are to be folded into the upcoming National Crime Agency (NCA), which is due to become operational by December 2013.

The NCA cyber unit will start operations on 1 October 2013, PCeU head detective superintendent Charlie McMurdie said in the statement.

"This is the first joint operation between the PCeU and SOCA cyber as we move towards full integration and inception of the National Cyber Crime Unit on 1 October 2013," said McMurdie.

"The dynamic nature and successful outcome of this operation, which has prevented distress and financial loss to numerous UK victims, clearly demonstrates the benefit of brigading resources and expertise in this increasing and specialist area of criminality."