Two people have been arrested on suspicion of murder.
They were detained on Saturday morning after police received call about an incident in St Stephen's Road, in the Highfields area of Leicester
Officers were called shortly after 8am to the three storey house.
A 23 year-old woman and a 34-year-old man have been arrested on suspicion of murder and remain in police custody.
The house and an alleyway, on the corner St Peter's Road, was cordoned off to allow forensic officers to carry out an examination of the scene.
Police say inquiries are in their early stages and detectives are working to establish the exact circumstances surrounding the incident.
No details of the alleged victim have been released.
Police believe there may have been a serious incident in the house, which is dived into flats, on Tuesday evening or the early hours of Wednesday.
Detective Inspector Simon Shuttleworth has launched an appeal for witnesses.
He said: "If you were in the St Stephen's Road area during the evening of Tuesday, February 17 and into the early hours of Wednesday, February 18, and saw any suspicious behaviour we would like to hear from you.
"Did you see or hear any thing untoward?
"Maybe you didn't think much of it at the time, but it could help us with our inquiries."
Mohsin Ahmed of the Naqshbandi Arshadia Youth Association said his organisation meets each Tuesday evening in the IMRA centre next door to the house.
He said: "We believe three people lived there.
"Often we could hear arguing coming from the house.
"At one time we offered them some food but they refused it."
University professor Abdulrehman Mohammad lives at the back of the house in Medway Street with his family.
He said: "We believe two people live in the house.
"They tend to leave the gate to alley way open.
"I looked out of the back window and saw the police tape across the alley.
"The police have not told us what has happened."
He added: "The police have been to the house before about six months ago. But we do not know what that was about."
Police are urging people with information about what happened to get in touch with us on 101, or call Crimestoppers, anonymously, on 0800 555 111."