An investigation has been launched after the bodies were found at an address in Colne Road in Reedley.
Detectives are appealing for information after officers were called at around 8.45 am on Thursday, October 1 to a report of a concern for safety at the address.
The responding officers found the bodies of two females inside the address and there was evidence of fire and smoke damage inside the house.
The woman has now been formally identified as Dr Saman Mir Sacharvi, aged 49. The body of the girl has yet to formally identified but is believed to be Dr Sacharvi’s daughter, 14-year-old Vian Mangrio, who was a pupil at Marsden Heights School in Nelson. The two lived together at the address.
A Home Office post-mortem has today revealed Dr Sacharvi died as a result of pressure to the neck. She had also suffered an assault.
Although the post-mortem investigation is ongoing for Miss Mangrio, and detectives cannot yet give a cause of death, police did confirm that she was found badly burnt inside the address.
A spokesman for Lancashire Police said: "Their next of kin have been informed and they are being supported by specially trained officers. Our thoughts are with them and all of those who knew Dr Sacharvi and Miss Mangrio, a pupil at Marsden Heights School in Nelson, at this time.
"Both deaths are at this stage being treated as unexplained and Home Office post-mortem examinations will be carried out in due course to try to establish the cause of death."
Supt Jon Holmes, Lancashire Constabulary’s Head of Major Crime, said: “This is a truly harrowing set of circumstances and my thoughts are very much with the loved ones of Dr Sacharvi and Miss Mangrio. They have my deepest condolences at this awful time.
“We are now treating the investigation as a double murder inquiry and although we are still in the relatively early stages we have a dedicated team of detectives and staff working on it. They are following a number of lines of enquiry to piece together exactly what has happened.
“I would now appeal to anyone with any information about these two deaths to get in touch with us.
“Perhaps you have seen something suspicious close to the scene in recent days or weeks, maybe you have CCTV or dashcam footage taken in the area that you can share with us, or perhaps you think you know who may be responsible. Even if you think that the information you have is insignificant, please come and speak to us and let us be the judge.
“We also recognise that this will have caused concern in the local community and we would like to reassure residents that we have extra patrols in and around the area. If anyone has information or concerns they can approach any of our officers.”
Anyone with information is asked to contact police as soon as possible through the dedicated Major Incident Portal at here or on 101, quoting log 0429 of October 3. Alternatively independent charity Crimestoppers can be reached anonymously on 0800 555 111 or at crimestoppers-uk.org.