"I am very sorry to learn about the passing away of your mother. This is an irreparable loss in which words are scant comfort," Singh said in his condolence message to Chidambaram.
"My deepest prayers are with you in this hour of grief," he said.
Chidambaram's 92-year-old mother, who was unwell for the past few days, breathed her last at her residence in Chennai this morning.