A man has been arrested on suspicion of murder by police searching for a missing woman.
Natalie Hemming, 31, of Alderney Avenue, Newton Leys, was reported missing on Tuesday.
The man, 42, and also from Milton Keynes, was arrested by Thames Valley Police earlier in connection with the investigation and is in custody.
Police said Ms Hemming’s disappearance was “out of character” and they are still trying to locate her.
Det Ch Insp Simon Steel said officers were “keeping an open mind” about the circumstances surrounding the disappearance.
“Our priority is to find Natalie and return her to her family as soon as possible. We would like to speak to anyone who has any information about where Natalie may be or anyone who has seen her since 3pm on Sunday.
“If you recognise someone fitting Natalie’s description or have any details which could assist with the investigation, no matter how insignificant you feel they may be, please contact police.”
Ms Hemming is described as white, about 5ft 3in (1.6m) tall, of slim build, has shoulder length brown hair and blue eyes.
She was last seen on Sunday at 15:00 BST in Hemel Hempstead, Hertfordshire, and was wearing a blue top, blue jeans and a short black jacket.