Three incidents have taken place in the last ten days in the Stranraer area.
The first was between 2 pm on Friday June 19 and 6 pm the next day when a ten foot trailer with five doors was taken from the Blackparks Industrial Estate. Its registration was S06 JNS.
A second trailer was stolen on Wednesday June 24 at about 6 pm from a long stay car park in Agnew Crescent, registration M735 HWO.
And the third theft took place overnight between Thursday June 25 and Friday June 26 from The Garage on Main Street, Stonykirk. It is described has having a wooden bed with the number plate PN02 FHU.
The value of the stolen trailers is over £5000 and police say they would all have required to have been towed by a vehicle with a tow bar fitted.
Anyone with information should call officers on 101.