The government's fraud investigating agency, the Serious Fraud Investigation Office (SFIO), has reportedly initiated a probe into alleged financial irregularities worth over Rs 8,000 crore at Kingfisher Airlines.

The agency has already sent notices to United Breweries, Kingfisher Airlines and United Spirits, said a CNBC-TV18 report, citing unnamed sources.

SFIO is expected to summon Vijay Mallya and executives of United Breweries and United Spirits, the report said.

The report said that the agency is carrying out an investigation into alleged mismanagement of funds from 2005 to 2014, which could have resulted in the grounding of the carrier.

The agency is currently examining the flow of funds between Kingfisher Airlines and group companies United Spirits and United Breweries, to identify the fraud.

The airline, grounded since October 2012, lost its flying licence on 31 December 2012 when aviation regulator Directorate General of Civil Aviation refused to renew the licence over the company's inability to provide a satisfactory plan to continue operations.

In May, a DNA report claimed that United Spirits (USL) chairman Mallya misused company funds worth ₹170 crore to buy shares of his IPL team Royal Challengers Bangalore (RCB) at ₹3,62,240 per share.

Besides, audit firm Price WaterHouse Coopers had revealed that USL funds were parked with other Mallya-owned companies from 2010 to 2014 without the consent of the company's shareholders.