Police on Friday found a vault-like concrete structure under the floor in Jamaluddin Sardar’s house in Sonarpur during a search that was witnessed by the man who has been accused of multiple assaults, officers said.

“Jamaluddin said the underground structure was built to store water. But our team did not find any water in it,” said officers of the Baruipur police district.

Trinamool had distanced itself from Sardar after allegations surfaced that he had tortured villagers in his house.

“We wanted to revisit the spot of the alleged crimes with the accused,” said an officer of Sonarpur police station.

Jamaluddin, in his late 40s, was arrested following complaints of moral policing, holding kangaroo courts and brutal assault on men and women.

He was rounded up on Friday last week from a place in Baruipur that borders the Kolkata Leather Complex.

Days before his arrest, a Sonarpur resident had alleged that Jamaluddin had hung her husband upside down and tortured him in his house. She also alleged that she had been assaulted and tied with chains when she protested the assault on her husband.

The police found steel chains and shackles in the house, officers said.