"Nobody is giving away Sir Creek to Pakistan.
But I don't know anything about the letter," Chidambaram said on a question regarding a letter written by Gujarat Chief Minister Narendra Modi to Prime Minister Manmohan Singh on Sir Creek.
"If anybody is suggesting that India is handing over Sir Creek to Pakistan, then it is a ridiculous suggestion," Chidambaram said.
Earlier in the day, Modi, in a letter to the Prime Minister as a concerned citizen, urged him to stop dialogue with Pakistan at once on the Sir Creek issue and demanded that it should not be handed over to Pakistan.
"I am writing on a serious issue of talks going on regarding Sir Creek being handed over to Pakistan. Any attempt to hand over Sir Creek to Pakistan would be a strategic blunder considering the history and sensitivity of the region," Modi wrote in the letter.
"I would earnestly request you to stop this dialogue with Pakistan at once and Sir Creek should not be handed over to Pakistan," he wrote.
Due to the election code of conduct, Modi wrote the letter as a concerned citizen and not as a chief minister of a state, BJP spokesperson Nirmala Sitaraman had said giving details of the letter.
Modi also raised the issue during his poll rallies in different parts of the state today.
Sir Creek is marshy water body along the India- Pakistan border, which is disputed and the two countries are bilaterally discussing the issue for quite a long time.