Mr Campbell said that three suppliers, Hilindi Pty Ltd, trading as R&R Tape Suppliers, Momar Australia Pty and NCH Australia Pty Ltd, would be examined over the next three weeks as the commission explored relationships with purchasing officers.

The Roads and Traffic Authority was also involved, as well as 88 councils and 22 other organisations. Councils involved included Ballina, Bathurst, Broken Hill, Burwood, Byron Bay, Botany, Lithgow, Liverpool, Narrandera, Orange, Sydney, Walgett, Waverley and Yass.

Gift vouchers sent to people in these 110 organisations over a period of a few years had come to $68,380 and the total value of gifts such as iPods, Parker pen sets, Driza-Bone jackets, camcorders, iPhones, DVD recorders, bottles of Scotch, and computer bags had come to $116,617.

The apparent corruption, uncovered by Operation Jarek, had come to more than $1.5 million, and ICAC regarded what it had uncovered as merely the ''tip of the iceberg''. In many cases, it had started with ''a case of beer or something at the end of the year'' and progressed to tickets for football, free holidays and collusion in false invoicing.

Martin Slade, a sales representative for Hilindi Pty Ltd, said yesterday he had dealt with various councils and had given vouchers for stores like Coles-Myer as a matter of course. The vouchers were in multiples of $50. Council officers had also expected it, including one from Byron Shire Council who had said when asked for an order: ''What's in it for me?''