A man and a woman who were murdered following an alleged assault are believed to have been stabbed, police have said.
The victims, both aged 26, died following a "disturbance" at a property in Red Lion Street, Boston, Lincolnshire, in the early hours of Sunday morning.
A 41-year-old man was arrested and questioned on suspicion of murder following the deaths.
Detective Chief Inspector Martin Holvey said: "Post mortem examinations of both victims were carried out overnight and the preliminary findings can be confirmed as consistent with stabbing.
"Detectives continue to question a 41-year-old local man on suspicion of murder.
"I am appealing for any witnesses who may have any information to contact Lincolnshire Police on 101."
A third person, a 24-year-old local woman, was also injured in the incident and was taken to Boston Pilgrim Hospital where she was treated for less serious injuries.
A police spokesman said an increased police presence remains in the area of Red Lion Street while the investigation continues.