Detectives say they are continuing to investigate how the pair died but have confirmed they are not looking for anyone else.
Staffordshire Police said post-mortem examinations brought no evidence of "overt injury" or causes of death and said further tests would now be carried out.
The man and woman have yet to be formally identified and both deaths are still being treated as unexplained.
Their bodies were discovered at a detached house on Hill Street at around 10.30am on Thursday.
Detective Inspector Cheryl Hannan, senior investigating officer, said: "We are not looking for anyone else in this enquiry, but my team is working hard to establish the circumstances of their deaths.
"Officers are no longer at the house, however detectives continue to follow up lines of inquiry and we would encourage anyone with information to call 101 quoting incident number 196 of May 16."