Japan's financial watchdog has told an investment firm to halt its operations on suspicion that it has lost most of the $2.3bn (£1.5bn) funds it manages.
Operations at AIJ Investment Advisors, which manages group pension funds for more than a hundred firms, have been suspended for a month.
It came after reports in Japan alleged that the firm may have covered up losses for years.
Authorities said they would also probe all other investment firms in Japan.
"The Financial Services Agency (FSA), together with the labour ministry, will take every possible step to prevent this kind of incident from happening again," said Shozaburo Jimi, the head of the FSA.
The report has taken analysts and industry watchers by surprise.
"It is very difficult to understand how they were able to hide all these losses," Yuuki Sakurai of Fukuko Capital Management told the BBC.
"They should have had accounting firms checking all their balance sheets."
At the same time, analysts said that investment firms also provided their clients with reports of how and where their money had been invested.
They said it was difficult to believe that none of the firm's clients has raised any concerns.
"It is a case of negligence at various different levels," Mr Sakurai added.
The financial watchdog said that it was still investigating the extent and scale of losses at the firm.
"AIJ cannot explain its asset management situation. The size and cause of the losses are now under investigation," an FSA official told a news conference.
'Will get sorted'
The news of AIJ's losses comes just months after another Japanese firm Olympus admitted that it hid $1.7bn in losses for as long as 20 years.
Analysts said that scandals may see changes being made to corporate laws in Japan.
"I am sure this will lead to a review of the checks and balances in place," said Gerhard Fasol of EuroTechnology.
However, industry experts believe that while these cases have been high-profile and may have raised concerns about corporate governance, it would be unfair to draw too many conclusions about the state of Japan's corporate culture.
"This has nothing to do with Japan's business culture. The reality is that not every person is true and honest," Mr Fasol said.
He added that once the investigations had taken place, those responsible would be held accountable.
"It may take time, but things will get sorted out," he said.