The controversy over Infosys Chief Mentor N R Narayana Murthy's remarks on the national anthem issue snowballed on Friday, with Karnataka police registering a case against him and the state government condemning them as an 'unpardonable offence'.

The Mysore City police registered the case against Murthy under Section 3 of the Insult to National Honour Act on the basis of a complaint lodged by an advocate.

"The case, registered as a non-cognizable offence, is under investigation," Karnataka Home Minister M P Prakash told the state assembly.

The controversy arose following a statement made by Murthy at a press meet he addressed later at which he defended the playing of instrumental version of the national anthem to avoid embarrassment to foreigners present at the function, he said.

"There was no need for Murthy to make such a comment," Prakash said.  "There are a lot of firms which employ foreigners in the city and also in the country.Everyone should understand his limitations and should not exceed it."

Earlier, Vatal Nagaraj (Vatal Paksha), who demanded a reply from the government on the issue, urged that Murthy should be deported from the state and his Infosys wound up.

"We don't need such companies," Nagaraj said.

When Nagaraj and some others objected to the statement by noted writer S L Byrappa defending Murthy, Prakash appealed to them not to rake up another controversy and to spare the writer.