Detectives investigating the murders of Colin Dunford and Julie Davison have obtained a warrant of further detention for the 36-year-old man arrested in the Leeds area early yesterday morning.
James Allen is in police custody in Middlesbrough undergoing questioning in relation to the two murders and a sexual assault.
James Allen, charged with the murder of two people last month, has been remanded in custody.
A man charged with the murders of a Teesside pensioner and a woman from North Yorkshire has appeared in court.
Police in North Yorkshire are appealing for information about a laptop that belonged to 50-year-old murder victim Julie Davison.