Anita Stevenson had been missing for over a month before she was discovered on land near Old Court House Lane in Bromborough in November.
Further tests have been ordered following a post-mortem examination to establish the cause of her death.
The arrested 41-year-old will face "no further action", police said.
Ms Stevenson was captured on CCTV near Albany Road in Rock Ferry on 18 October, wearing a blue Adidas jacket and Nike leggings and trainers.
Merseyside Police said the investigation into her disappearance and death was ongoing.
A man arrested on suspicion of murder after a woman's body was found in woodland in Wirral has been released without charge.