Officers have dealt with a number of incidents of illegal poaching in the Leighton Moss, Warton and Hale areas.
It is believed that a group may be using high powered lamps, dogs and firearms to hunt and shoot deer in the area.
PC Andrew Massingham, Lancashire Police Wildlife Officer, said: “Wildlife crime and issues such as deer poaching are just as serious as other crimes and it tends to be committed by serious and organised crime groups who profit from the sale of carcasses and venison meat.
“This is not humane and these individuals are carrying out indiscriminate slaughter on a commercial scale with deer being taken regardless of species, sex or season, where they have no permission or authority to do so.
“We are committed to tackling rural crime and our wildlife officers will continue to work closely with the community, local landowners, legitimate deer stalkers and other agencies such as the British Deer Association to stop the poaching and bring those responsible to justice.
“Anyone caught poaching illegally should be warned that they could be prosecuted.”
Officers have already made three arrests in connection with illegal poaching activity. A 24-year-old man from Carnforth, a 46-year=-old man from Preston and a 50-year-old man from Preston have been bailed until January 2015.
Call police on 101 or alternatively, contact Crimestoppers anonymously on 0800 555 111 or online at Crimestoppers-uk.org.