Tax officials who conducted search operations at the offices of the Bengal Cricket Association and Shah Rukh Khan's Kolkata Knight Riders till the early hours of Thursday here claimed to have found "incriminating evidence" of irregularities.

"We have found incriminating evidence. We will investigate further. We needed to have a look at certain transactions and we've found whatever we were looking for," said Indian Revenue Service Deputy Director Akhilendu Jadhav.

The main angle that the sleuths of the Directorate of Income Tax Investigation were looking for on the probe into the Indian Premier League (IPL) franchises was the legality of money transfers from tax havens abroad, primarily Mauritius, officials explained.

This apart, officials of the Directorate of Enforcement were probing the legitimacy of transactions between the franchise and the state's cricket board, the officials added.

Searches at both the board's office at the Eden Gardens stadium and the premises of Kolkata Knight Riders and its parent Red Chillies Entertainment of actor Shah Rukh Khan at ITC Sonar Bangla and Shakespeare Sarani began at 3 p.m. Wednesday.

The federal revenue department had Wednesday broadened the probe into the financial deals of IPL, even conducting search operations on three of its event management and broadcast firms in Mumbai, apart from the franchises.

The 10 franchises under scrutiny are Kochi's Rendezvous Sports, Pune's Sahara group, Mumbai Indians, Delhi Daredevils, Kolkata Knight Riders, Royal Challengers Bangalore, Deccan Chargers, Chennai Super Kings, Rajasthan Royals and Kings XI Punjab.