LONDON (AP) ― The ousted chief executive of Japan’s Olympus Corp. says the company isn’t doing enough to investigate a massive $687 million payment to mysterious financial advisers as part of a takeover.

The camera and medical device maker says outside lawyers and accountants will be part of what it called an independent review.

But former CEO Michael Woodford on Saturday dismissed the gesture, contending that the review isn’t genuinely independent.

“You need forensic accountants going in quickly, very quickly,” Woodford said in an interview with the Associated Press.

Olympus shares lost half their value ― shedding more than $4 billion ― during the week in the fallout from Woodford’s dismissal and his allegations of financial wrongdoing.

Woodford says he was fired for asking questions about the $687 million paid to financial advisers as part of Olympus’ purchase of U.K.’s Gyrus Group PLC.

The payment represented more than a third of the $2 billion purchase. Fees for advisers are normally 1 to 2 percent of the deal value.

“Why do you need a committee to say there’s $687 million for advice you can’t justify? Start with that before you move on,” Woodford said.

“It’s deliberate tactics, just to push it away, get it out of the spotlight.”

Olympus confirmed the $687 million figure on Wednesday, a day after chairman Tsuyoshi Kikukawa said the payment was about $390 million.

David Herro, chief investment officer for international equities at Chicago-based Harris Associates which holds a 2.5 percent stake in Olympus, gave a qualified welcome to the company’s move.

“We see it as a promising sign that Olympus has indicated it will appoint a panel to look into these acquisitions, but we’ll reserve judgment until we hear more details, such as who will be on the panel, what they will specifically be investigating and how quickly they will get this done,” Herro said Friday in a statement.