Police have revealed that a post-mortem examination into the cause of George Michael's death was "inconclusive".
Thames Valley Police said in a statement that more tests will now be carried out to determine what the cause of death was. The results of these tests are not likely to be known for a number of weeks.
While the death is still being treated as unexplained, it is not suspicious.
Police will prepare a file for the Oxfordshire coroner.
The singer died on Christmas Day at his Oxfordshire home.