Thieves pretended to be police officers after breaking into a house and then locked the victim in a bedroom while they searched the rooms.
Two men entered the house in Hodge Court, Kettering, yesterday (Monday) via an unlocked window and when challenged, told the victim they were police officers.
They then searched her before locking her in a bedroom and searching the rest of the house, making off with a mobile phone and jewellery.
The woman was unharmed but left shaken by the incident, which took place between 1pm and 2pm.
Both offenders were white men, aged 20 to 25, clean shaven, about 5ft 10in and of slim build.
One wore a brown hooded top which had a white liner, with white trainers, blue jeans and spoke with an English accent.
The second offender was carrying a crowbar.
Witnesses or anyone with information can contact police on 101 or Crimestoppers anonymously on 0800 111555.