Angela Holgate, 54, and 75-year-old Alice Huyton were discovered by a relative at Mrs Holgate’s home near Southport on Saturday evening.
Merseyside Police last night confirmed it had launched a murder investigation, with detectives wanting to speak to lodger Barry Morrow, 51, who lived with divorced Mrs Holgate.
Police fear he may have fled the country to either France or Spain.
Post-mortem examinations to establish how the two murdered women died continued throughout the night, with the results expected to be released in the coming days.
Mrs Huyton was last seen on Friday evening when she left her home in Southport to visit her daughter.
Chief Superintendent Nikki Holland said: “We are investigating the tragic deaths of these two women and our sympathy goes to their families.
“Detectives are investigating the circumstances around these deaths and are trying to piece together the women’s last movements.
“We are appealing to anyone with any information that may help us with this investigation to come forward as soon as possible.
“In particular we are keen to trace Mr Morrow, who lived at the house for a period of time and who we believe may have vital information for this investigation.”
Mr Morrow is described as white, 5ft 7in, of medium to stocky build with straight, short brown hair that is receding and blue eyes.
Mrs Holgate’s white Citroen with the registration PN11 RWK is also missing.
her house remained sealed off on Sunday as police carried out forensic examinations of the scene.