The union government has ordered an investigation by the Serious Frauds Investigation Office (SFIO) into the Satyam Computer Services scam even as a group of Mumbai-based investors - the Small Investors Grievances Forum - said it would file a public interest litigation in the Bombay High Court tomorrow demanding an independent investigation into the Rs7,000-crore fraud.

''The regulatory mechanism has failed entirely. We are demanding an independent investigation in the case,'' reports quoted Kirit Somaya, president of the forum and a former member of Parliament, as saying.

The PIL would have market regulator SEBI, auditor PriceWaterhouseCoopers, the union government and the apex body of auditors ICAI amongst others as respondents.

The government has asked the Serious Fraud Investigation Office (SFIO) to investigate the Satyam scandal and also to look into the role of auditing firm PriceWaterhouseCoopers in the Satyam fiasco, said minister of company affairs Prem Chand Gupta.

Announcing this at a press conference, Gupta said the SFIO will also investigate the role of auditing firm PriceWaterhouseCoopers (PWC) in the Satyam fiasco as the new board reviews the situation. The SFIO will submit its report on the Satyam fiasco within three months, he added.

A preliminary investigation by the Registrar of Companies meanwhile, found that Satyam founder Ramalinga Raju had several benami accounts.

The SFIO probe has been ordered after receiving a report from the Registrar of Companies (RoC), Hyderabad, which inspected the books of accounts of Satyam Computer Services and eight other companies belonging to relatives of Satyam founder and former chairman B Ramalinga Raju.

Officers of the state intelligence department, meanwhile, raided the office of auditing firm PriceWaterhouseCoopers in Hyderabad and confiscated several laptops and important documents. 

PWC is being investigated for failure to detect anomalies in Satyam's balance sheet, which, analysts say, could have easily been detected during the auditing.