Flowers and tributes left by mourners in Camden Square outside the house of Amy Winehouse. (AP Photo/Lefteris Pitarakis)

Meanwhile, an autopsy on Monday failed to determine what killed the troubled 27-year-old singer. Police said that a forensic post mortem “did not establish a formal cause of death and we await the results of further toxicology tests.” The results to those tests are expected to take two to four weeks.