Many Independent Insurance staff in the company's savings-related share scheme opted to turn their savings into Independent shares – now thought to be worthless – on June 1 this year.
The scheme matured a week after actuaries Watson Wyatt sent a letter to Independent's board warning of financial difficulties on May 25.
Insurance Times has been advised that Independent directors could be found guilty of insider dealing if they had warned employees not to buy the shares.
It is said the maximum amount that could be used to buy shares under the scheme was £14,000, although there have been reports that one senior manager spent as much as £250,000.
Meanwhile, HSBC has confirmed reports that Independent Insurance founder Michael Bright took out a £4m personal loan, secured against his shares in the company.
Bright's personal share in the company was once worth £60m.
A HSBC spokesman would not comment on any individual's dealings with the bank but said that anyone in a similar situation would now be in talks about alternative methods of repayment.
Bright stepped down as chief executive of the company in late April, then quit as non-executive deputy chairman last week without compensation.
He also resigned as president of the Chartered Insurance Institute this week, with deputy president Lillian Boyle assuming the reins.
The institute held a management meeting on Wednesday night (June 20) to decide a future course of action.