The couple identified as Ankur Sarma and Jonali Devi were staying in a rented accommodation in Pathsala of Barpeta district, they said.
According to the husband, he saw some unidentified men inside the house when he had gone to the bathroom in the wee hours today, police said.
He claimed that the men overpowered him and tied him up, following which he passed out, they said.
"Ankur said after that he did not know anything and in the morning he saw his wife's body," a police officer said, adding, that then he shouted for help and the owner of the house came to his rescue and informed the police.