An SFO spokesman last night confirmed to Amateur Photographer that the SFO inquiry is ‘ongoing’.

The SFO launched its investigation in November 2011 after ousted Olympus CEO Michael Woodford submitted documents alleging a cover-up at the firm.

The whistleblower, who was based in Japan, was sacked after protesting that Olympus’s payment of a $687m fee in connection with the acquisition of UK medical firm Gyrus, in 2008, was suspiciously high.

Olympus later admitted that the inflated funds – along with other transactions – were used to cover-up losses Olympus had suffered on investments dating back years.

Last week, ex-president Tsuyoshi Kikukawa, along with former executive vice-president Hisashi Mori and Hideo Yamada, a former Olympus auditor, pleaded guilty in connection with a £1.1 billion accounting cover-up.

The three could face up to 10 years in jail after pleading guilty to filing false financial statements.

Olympus Japan declined to comment on the case on the basis that the accused are former employees.

Meanwhile, Woodford’s account of the multi-million-dollar scandal is due to be published on 29 November, according to the book’s UK publisher, Penguin.

Called Exposure, the book will recount the Briton’s experiences of a crisis that struck at the heart of corporate Japan.

In May, Olympus agreed to pay Woodford £10 million in an out-of-court settlement after he sued his former employer for wrongful dismissal.

The SFO says its investigations can take 18 months before reaching court.