Officers received a call from East Midlands Ambulance Service at 10.30pm on Monday 10 May who were attending the house in Chapel Street.
The woman was found with serious injuries and was taken to Leicester Royal Infirmary.
She died in hospital later later that evening.
A 62-year-old man from Blaby has been arrested in connection with the incident and remains in police custody.
Police said the man was known to the woman.
A cordon remains in place at the property while enquiries continue. Officers are carrying out house to house enquiries.
Detectives are also appealing to anyone who was in the Chapel Street area of Blaby on Monday afternoon or evening and who has any information to make contact.
Detective Inspector Kenny Henry, who is leading the investigation, said: “Our enquiries are in their early stages and we have a dedicated team carrying out a full investigation into this incident to establish the full circumstances.
“While we understand the incident has happened inside a property, I am appealing to anyone who was in the area on Monday afternoon or evening and who has any information to get in touch with us – no matter how insignificant the information you have may seem. Did you see or hear anything in the area that caused you any concern? Do you have any CCTV or dashcam footage from the area which could assist with our enquiries?"
Lake search for missing boy
A Warm Welcome to the Community for Hinckley
Warwickshire Recycling Centres to Temporarily Close During Peak Heat Hours
Leicestershire Recycling and Household Waste Sites to Close Early Due to Hot Weather
Two men charged in connection with Fire Arms incidents
£26m for new ambulances & crews in East Midlands
Primary school to close due to lack of teachers
