A panel set up to investigate the Olympus Corp scandal wants to hear from the firm's ousted British chief executive and will need at least a month to report its findings, the group's head said on Wednesday.

Heeding calls for an independent probe, Olympus named six men on Tuesday who will investigate M&A deals that set off a public boardroom battle and wiped out half of the 92-year old company's market value.

The probe will focus on a record $687 million advisory fee paid as part of a $2 billion purchase of British medical equipment maker Gyrus in 2008.

It will also scrutinize the acquisition of three companies in Japan that Olympus, under chairman Tsuyoshi Kikukawa's decade-long reign at the company, later largely wrote off.

Tatsuo Kainaka, a former supreme court justice who earlier this year headed a probe of Japan's No.2 bank, Mizuho Financial Group, told Reuters in an interview the panel had a wealth of experience to help it conduct the investigation.

In a sign of growing alarm that the scandal may hurt investor confidence in Japan as a marketplace, the ruling Democrats plan to set up their own panel to debate improving corporate governance and disclosure, a senior party official said on Wednesday.

Olympus on Tuesday named six men to look into the controversial deals that came under the spotlight after Olympus ex-CEO Michael Woodford went public, saying he was sacked for asking too many questions about the deals.

Kainaka said the panel will want to question the Briton as part of its inquiry.

We will seek the cooperation of Woodford, he said.

Olympus says it did nothing wrong and insists the Briton had to go because he was a poor manager.

A review in 2009 commissioned by Olympus' auditing board cleared management of misconduct in the now-controversial acquisition of the three Japanese firms.


But since Woodford's ouster Olympus has been under growing pressure to reveal the details behind the acquisitions, even after Kikukawa resigned. The third-party panel aims to stem an exodus of irate investors.

While politicians and Japanese media were slow at first to react to the scandal, they later weighed in. A senior Democrat lawmaker called on financial watchdogs to investigate the matter and Prime Minister Yoshihiko Noda asked for clarification of the matter.

Seeking to assure skeptical investors, Olympus has said none of the six members of an all-Japanese committee has had any previous association with the company.

The group, besides Kainaka, includes lawyers and an accountant with experience investigating governance at a bank, power company and consumer electronics maker.

Among its members is Hideki Nakagome, a retired judge who served on a panel investigating Tokyo Electric Power's nuclear accident at its Fukushima plant.

Also named was ex-prosecutor Tomoyoshi Arita and two lawyers from private practice, Eiji Katayama and Osamu Sudo. The latter chaired a group investigating JVC Kenwood Corp, which last year was forced to issue a warning about its status as a going concern. Katsuaki Takiguchi, an accountant, rounds off the panel.

Katayama, Sudo, Kainaka and Nakagome have not handled cases involving mergers and acquisitions, legal filings from legal publisher Westlaw Japan's database show.

The head of the Tokyo Stock Exchange on Friday criticized Olympus management for its handling of the crisis and warned that it risked legal action from shareholders unless the probe was truly independent.

(Writing by Tim Kelly and Tomasz Janowski)