The Tamil Nadu Assembly Privileges Committee on Monday issued a notice to the Dravida Munnetra Kazhagam (DMK) working president M K Stalin and 20 other legislators of his party for having brought Gutkha, a banned product, into the House in July.
The committee is led by Pollachi V Jayaraman, who is also the deputy Speaker of the assembly.
Sources said the panel has sent notices to the DMK MLAs seeking their explanation within a week.
The notices were sent after scrutinising the assembly proceedings' footage of July 19 when members of the main opposition had held up Gutkha pouches.
DMK legislator S Regupathy told reporters here that what his party MLAs had done was their "democratic" duty.
It was to demonstrate that banned Gutkha was available and action should be taken to halt it, he said.
Senior Communist Party of India (CPI) leader D Pandian said similar instances were seen in assemblies elsewhere to drive home various point like "presence of rotten rice", adding that likewise Opposition leader Stalin had raised the Gutkha matter in the House.
On July 19, DMK MLAs led by Stalin had created a furore in the assembly when they held up Gutkha sachets, prompting Speaker P Dhanapal to refer their action to the Privileges Committee.
The Speaker had then said that the DMK MLAs' action amounted to "breach of privilege". During the debate, that day in the House, leader of the opposition Stalin sought to raise the issue of alleged availability of Gutkha in the state.
The issue of 'gutkha' (a mixture of chewing tobacco and betel nut) has created a political furore in Tamil Nadu.
Searches by Income Tax authorities in the premises of a gutkha manufacturer in Chennai last year had led to the unearthing of documents claiming a "payout" to a minister and officials including a senior police officer, as a quid pro quo for overlooking the sale of the banned product.
Ever since the matter came into the limelight, the opposition DMK has been targeting the ruling AIADMK (All India Anna Dravida Munnetra Kazhagam) for allegedly allowing Gutkha sale and the alleged graft involved in it.