A 47-year-old man from Neston, a 40-year-old man from Raby Mere, Wirral, and another man and a woman, both aged 18 and from Thornton Hough, have all been arrested in connection with Ms Pye's death.
"I would appeal to anyone who was driving along the M53 motorway just before, or just after, midnight who may have seen anything which could help with our investigation to contact the police on 0151 777 2265, or Crimestoppers on 0800 555111," said Detective Chief Inspector Mark Parkinson of Merseyside police.
"We believe that the deceased had been to a party on Sunday night and would appeal to anyone who may have further information which could help us build a picture of the events leading up to this lady's death to contact us."
A post-mortem into the woman's death is currently being carried out, DCI Parkinson added.
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