The National Crime Agency is reviewing all of its criminal investigations after a succession of blunders led to the collapse of multi-million pound money-laundering cases.
The NCA accepted yesterday that "incompetence" was to blame for the collapse of two cases and said it was reviewing all current warrants used to raid homes, search houses and seize banking records.
The review was launched in September and officials are expected to examine more than "2,000 different parts of documents", amid concerns that further court cases could collapse.
In May, i reported the scathing criticisms of the agency by a High Court judge after officers unlawfully used search warrants to plant a surveillance device without warning magistrates. Mr Justice Hickinbottom described the agency as "remarkably ill-informed" and "ignorant" about search warrant procedures.
The case related to an NCA money-laundering investigation involving a family that runs a £60m business empire including hotels and nursing homes. The judge said the NCA "acted with patent and egregious disregard for, or indifference to, the constitutional safeguards" and that the failings were highly likely to occur again.
The NCA said yesterday that it had improved training as a result of the mistakes.
The NCA review comes as Lynne Owens was appointed director general of the agency. The chief constable of Surrey Police will become Britain's most senior woman police officer when she takes over the £214,000 a year role in January.