A 44-year-old woman has been arrested after a doctor and her teenage daughter were found dead following a house fire in Burnley.
The bodies of Dr Saman Mir Sacharvi, 49, and Vian Mangrio, 14, were discovered at their smoke and fire-damaged house in Reedley, on October 1.
Dr Sacharvi was found to have been assaulted and died from pressure to her neck, police said.
On Thursday, Lancashire Police arrested a 44-year-old woman on suspicion of perverting the course of justice and aiding and abetting murder. She remains in custody.
A 51-year-old man from Burnley, arrested on Sunday, is being held in custody on suspicion of two counts of murder, two of rape and arson with intent to endanger life.
A 56-year-old man arrested at the same time has been released without charge.
The second victim has yet to be formally identified, but is believed to be Miss Mangrio.
The post-mortem investigation remains ongoing, so a cause of death has not been established for her, but police said she was found badly burnt at the address.
Her mother, understood to be originally from Pakistan, was a junior doctor.
She had been working with Lancashire and South Cumbria NHS Foundation Trust’s specialist perinatal community mental health team since February.
Anyone with information is asked to contact police on 101, quoting log 0429 of October 3rd.