Malcolm Naden. Image from New South Wales Police MediaPolice are facing a number of challenges in their search for accused double murderer Malcolm Naden.

Northern Region Assistant Commissioner Carlene Yorke, who has taken over the investigation, said the area around Nowendoc in the Barrington Tops National Park includes rugged terrain which can be physically gruelling and reduces visibility.

“Our tactical operations unit officers are trained in bush survival and undergo extensive training with other agencies to ensure they are at the top of their game,” she said.

“They are being assisted by the Dog Unit and PolAir, however, the weather conditions and visibility are hampering the search efforts.”

Naden, an experienced bushman, has been on the run for six years since he became a suspect in the murder and dissapearence of the two women in Dubbo.

He is also accused of shooting a 33-year-old officer with a single rifle shot on Wednesday morning as police attempted to corner him at a remote campsite, near Nowendoc.

NSW Premier Barry O’Farrell announced on Friday that he had increased the reward for information leading to Naden’s capture from $100,000 to $250,000.

Police have refuted claims that Naden had been spotted in the Lismore area of New South Wales.