Julie Finley, who was believed to have been a drug addict who mixed with prostitutes, was strangled.
But police said they had not yet established if she had been working as a prostitute. The murder squad will be checking for possible links with recent killings in the north-east Midlands - though police said there was nothing at present to link Julie's death to any others.
Her body was discovered in a field near a lay-by off the A570 Rainford by-pass near Skelmersdale, Lancashire, on Saturday afternoon. Police said injuries to her upper body and arms suggested a fight or scuffle, but there were no signs of a sex attack.
Ms Finlay who was 5ft 3ins tall and weighed six and a half stone, had not been living with her parents, Albert and Patricia Finley, at their home in Liverpool for several months. Police were trying to establish where she had been staying. She last visited her parents on Friday afternoon.