A post-mortem examination on singer Amy Winehouse failed to determine how she died and more toxicology tests are being carried out, with the results expected in two to four weeks, police said yesterday.

The autopsy was carried out after an inquest into the 27-year-old’s death opened and adjourned.

The “Back to Black” singer, who has fought drug and alcohol addictions, was found dead at her north London home Saturday afternoon.

As sales of Winehouse’s music soared and speculation swirled about the release of a possible posthumous album, her father Mitch visited a growing shrine outside the house.

Surrounded by television crews, well-wishers, and a swarm of teddy bears, flowers and the occasional bottle of booze, he read the dozens of condolence messages left for Amy.