Commonwealth organising committee chief Suresh Kalamdi was questioned on Wednesday by the CBI in connection with alleged financial irregularities in the conduct of the sports event.

Kalmadi reached the CBI office at about 10 AM. His questioning began about half an hour later, official sources said.

The questioning is about alleged irregularities in the Queen Baton's Relay held in London last year besides certain contracts awarded to various firms totalling several hundred crores, the sources said.

The agency had raided his Pune and Delhi premises on December 24 during which several documents including digital were seized, they said

The sleuths have grilled Kalmadi's three key aides in connection with the scam. The sources said Manoj Bhori, political advisor to OC head and P K Srivastava and A K Sinha, both assistants to Kalmadi, were also called for interrogation.

Besides Kalmadi, the CBI had also conducted raids at the residence of OC Secretary General Lalit Bhanot, R K Sacheti, who is Joint Director General of the OC, and Sangeeta Welingkar, member of the Games Image and Look Group.

The agency has so far filed three FIRs in connection with the alleged financial irregularities.