A total of 19 clients of rogue private eyes are to be investigated for illegal activity, the data watchdog has confirmed.
In a letter to Keith Vaz MP, Information Commissioner Christopher Graham said 125 victims were believed to be affected by the companies and individuals under criminal investigation for data protection breaches.
Five retailers, four legal firms, three insurance companies, two financial businesses, a construction firm and a security company are among those suspected of dealing with private investigators who broke the law.
Mr Graham and his office were initially handed a list of 98 clients of corrupt private detectives by the Serious Organised Crime Agency (Soca).
The so-called “blue-chip hacking” list relates to Soca’s Operation Millipede, which led to the conviction of four private detectives for fraud last year.