The general argues that the Tamil Tigers are on the verge of defeat
The Indian government has protested to Sri Lanka over a statement by the Sri Lankan army commander who described some Indian politicians as "jokers".
In an interview with a state-run newspaper, Lt Gen Sarath Fonseka said that the Indian government would not listen to Tamil Nadu "jokers".
The Indian state of Tamil Nadu has a population of about 65 million people.
It is overwhelmingly made up of Tamils, some of whom are sympathetic towards the Tamil Tiger rebels of Sri Lanka.
"If the Tamil Tigers are wiped out, those political jokers... who sympathise with them will most probably lose their incomes from them," Lt Gen Fonseka was quoted by the state owned Sunday Observer as saying.
He was commenting on the recent protests in Tamil Nadu against Sri Lanka's military offensive in the north of Sri Lanka.
A spokesman for India's Ministry of External Affairs, Vishnu Prakash, told journalists in Delhi that the Indian High Commissioner in Colombo, Alok Prasad, had taken up the issue "strongly" with the Sri Lankan authorities.
"The defence secretary of Sri Lanka promised to look into the matter and conveyed regrets should any such comment have been made," Mr Prasad said.
It is not the first time that Gen Fonseka's remarks have created controversy.
In October, British parliamentarians criticised his remarks to a Canadian newspaper that minorities in Sri Lanka should not make "undue requests".
The general was reported to have remarked that Sri Lanka belonged only to Sinhalese people.
In July, Sri Lanka's main opposition party accused Gen Fonseka of being behind violent attacks on reporters.
Opposition MP Joseph Michael Perera told parliament that the attacks were carried out by a "special team" controlled by him.
The army denied that it was in any way involved in attacks on journalists.
Gen Fonseka narrowly escaped death when a woman suicide bomber targeted him in April 2006 inside the high security army headquarters complex.