The National Broadcasting and Telecommunications Commission (NBTC) is conducting a probe into alleged collusion in the bidding process of its own 3G auction, reports the Bangkok Post.

AIS, DTAC and TRUE, the three bidders and winners in the 3G auction, have reportedly paid half the bid price to the NBTC after it formally declared them winners on Oct 19.

With NBTC's announcement of the 3G auction probe and delay in issuing 3G licenses, AIS and TRUE have publicly threatened to sue the NBTC if it fails to issue 3G licences by mid-January 2013, as reported here.