A terrace house in Portavogie was targeted in a suspected arson in the early hours of Thursday morning.
Police said the property on the New Harbour Road was attacked sometime around 3.30am.
No one was in the home at the time of the attack, which was extinguished by the Northern Ireland Fire and Rescue Service.
The PSNI is appealing for anyone who may have witnessed anything suspicious in the area to contact them.
A police spokesperson said: "The fire was started in the ground floor area of a mid-terrace house on the New Harbour Road sometime around 3.30am.
"Officers attended the scene along with colleagues from the Northern Ireland Fire and Rescue Service, who extinguished the blaze, which is believed to have been started deliberately. There was extensive damage caused to the house and thankfully, no one was injured, as the house was not occupied at the time.
"Our enquiries are ongoing, and we are appealing to anyone who was in the area at the time and saw anyone acting suspiciously to contact detectives on the non-emergency number 101, quoting reference number 193 of 30/12/21.
"You can also submit a report online using our non-emergency reporting form via http://www.psni.police.uk/makeareport/.
“Or, you can contact Crimestoppers anonymously on 0800 555 111 or online at www.crimestoppers-uk.org/.”