Police have arrested a Sage employee in connection with a data breach at the accounting and payroll software provider that may have compromised the bank account details of employees at 230 UK companies.

The City of London Police detained a 32-year-old female employee of the company at Heathrow airport on Monday on suspicion of conspiracy to defraud. She has since been bailed, according to the FT.

On Saturday, Sage revealed that it was warning over 200 of its business clients that employee salary information and bank account details may have been compromised in the hack.

"We are investigating unauthorised access to customer information using an internal login," Sage said. "We cannot comment further whilst we work with the authorities to investigate — but our customers remain our first priority and we are speaking directly with those affected."