A telephone company cut off an FBI international wiretap after the agency failed to pay its bill on time, according to a US government audit.
The Justice Department's inspector general criticised the FBI for poor handling of money used in undercover investigations, which it said made the agency vulnerable to theft and mishandled invoices.
It cited the case in which a wiretap under the Foreign Intelligence Surveillance Act (FISA) was disrupted due to an overdue bill.
"Late payments have resulted in telecommunications carriers actually disconnecting phone lines established to deliver surveillance results to the FBI , resulting in lost evidence, including an instance where delivery of intercept information required by a . . . FISA order was halted due to untimely payment," the audit said.
The FBI said no investigations were adversely affected by the incident.
The audit followed a 2006 case in which an FBI employee pleaded guilty to stealing more than $25,000 in confidential case funds intended for undercover telecoms services.
The FISA programme, denounced by critics as overly intrusive and unconstitutional, is up for renewal in Congress.
