A man has been charged with the murder of Bridget Simmonds.

Police confirmed a 57-year-old man had been charged and is due to appear in the Whangārei District Court this afternoon.

The murder charge comes after the body of the 43-year-old victim was excavated at a rural property at Parakao, west of Whangārei, on June 12.

Police converged on the 20ha block of land on Wilson Rd, 40km west of Whangārei, after new information came to light which caused investigators to believe foul play was involved in the disappearance of the mother of two.

Simmonds, of Northland, was last seen in February last year.

Detective Senior Sergeant John Clayton said the murder charge marked the end of a "lengthy investigation" that had involved hundreds of hours of police work.

Clayton said he hoped it could bring the victim's family some degree of closure after what had been an "incredibly difficult" year for them.

After the discovery of Simmonds' body, police arrested the man on assault charges.

Police said at the time that further charges were likely.

Simmonds, who was 42 at the time, was last seen at Countdown on February 23 and was reported missing on March 6 after all communication with her family stopped.

Simmonds' mother said last week that her daughter's disappearance was hard for all the family and it was like living a recurring nightmare.

"I hope police can get some answers because for me this is constant. It's like you are living it over and over every day and there's no end to it," she had said.