The first inquiry, set out in January 2016, stems from a report that found that senior managers were responsible for the bank's collapse in the 2007-09 financial crisis.

The second relates to events surrounding the discovery of misconduct within the HBOS Impaired Assets team based in Reading, west of London, which dealt with companies in financial distress. The FCA's civil investigation was reopened in April after former HBOS bankers were jailed in February.

"We are ... joining it with the investigation that we announced in January last year," Financial Conduct Authority Chief Executive Andrew Bailey told the watchdog's annual meeting on Tuesday.

Bailey said that police had recently passed on evidence from the trial to the FCA and the information is now being absorbed by the watchdog.

"It will be completed as soon as is possible. I can't put a date on that," Bailey said.

He later clarified to reporters that evidence from the trial would feed into the investigation of senior officials, who have not been named.

"There are two cases and the cases remain separate, but the evidence from Reading obviously informs the ongoing case," Bailey told reporters.

Bailey said there would be separate outcomes from the two investigations.

(Reporting by Huw Jones; Editing by Kirstin Ridley and David Goodman)