Separately, the Financial Reporting Council said it would investigate the firm's accounts.
The firm is already under investigation by the Financial Conduct Authority (FCA) for alleged accounting irregularities.
Quindell said it would "continue to co-operate" with the authorities.
The company has belatedly released its 2014 annual report. Trading in its shares was halted on 29 June, awaiting the results. It has asked for them to be traded again from Thursday.
It reported a £238m loss for 2014 and restated many of its earlier results.
The company's recalculations turned the 2013 profit after tax of £83m into a loss of £68m, and reduced reported net assets from £668m to £446m, as of the end of 2013.
Quindell also said it planned to hire a new chief executive and begin a review of the business.
Quindell has previously admitted that some of its accounting polices were "aggressive".
The group has been conducting its own review, advised by accountancy firm PricewaterhouseCoopers (PwC).
That review concluded that accounting policies relating to revenue and acquisition costs in some of its businesses - since disposed of - were "at the aggressive end of acceptable practice".
PwC also found that some other policies were "not appropriate", the company said.
Investors saw more than 80% wiped off the value of their shares in a disastrous 2014, as rumours of the accounting irregularities emerged.
The Serious Fraud Office said it has opened a criminal investigation into insurance technology and claims management group Quindell.