Bangalore, Feb. 16: A retired mathematics professor of the Indian Institute of Science, his wife and mentally challenged son were found murdered at home today.

Police forced their way into P.L. Sachdev’s bungalow in Bangalore’s upscale Rabindranath Tagore Nagar, where many politicians live, after a complaint by a relative whose calls to the family had gone unanswered.

As the police entered the house, locked from outside, they found the professor, in his mid-sixties, his wife Rita, 60, and son Munna, 35, in different rooms on the ground floor, strangled to death. The professor had been strangulated with a dupatta while a piece of wire was found around his wife’s throat.

Rita was a housewife. The police said Munna was mentally challenged.

“We have some clues,” said M.R. Pujar, the additional commissioner, law and order. Nothing in the house seemed to have been disturbed and no valuables appeared to have been taken, he added.

The professor’s younger son Anurag, 23, told the police he had gone to see his girlfriend on Friday and was away through the weekend. He returned today after the murders came to light. Sources said Anurag was a college dropout.

“The motive for the crime has not been ascertained,” said S.U. Hussain, the deputy commissioner of police (north).

The Sachdevs had gone for dinner with Amit, a relative from Goa, on Saturday, he said. Yesterday, when his calls went unanswered, Amit visited the house and found it locked. Today, he called the police.

Sachdev “was a very distinguished scientist, a Fellow of all the three science academies in India”, an IISc professor said, referring to the Indian National Science Academy, Indian Academy of Sciences and the National Academy of Sciences.