Hoffman body tests 'inconclusive'
Tests on the body of actor Philip Seymour Hoffman are inconclusive, New York's city medical examiner has said.
Spokeswoman Julie Bolcer said further tests were needed to determine what caused his death.
The Oscar-winning star, 46, was found dead at his Greenwich Village home on Sunday with a syringe in his arm.
Police later arrested four people on drug charges. It is not clear whether the move is linked to drugs found at the actor's home.
On Wednesday, Ms Bolcer also said there was no timetable for finishing the post-mortem examination.
The spokeswoman also declined to elaborate on what further tests were needed.
However, toxicology and tissue tests are usually done in similar cases.
Philip Seymour Hoffman
1 best actor Oscar for Capote, 2005
3 supporting actor Oscar nominations
51 feature film releases, 1991-2014
29 dramas, 21 comedies, 1 animation
4 real life characters played: Lester Bangs, Truman Capote, Art Howe, Gust Avrakatos
After Hoffman's death, police found dozens of suspected heroin bags near his body.
Some were stamped with the ace of hearts and the ace of spades, which are said to be brand names for heroin that street dealers use.
Police are still trying to piece together his final hours using surveillance video and inspecting computers found in his home.
Police officials say the heroin found in Hoffman's apartment was not mixed with the synthetic narcotic fentanyl.
Fentanyl has been blamed for a number of recent overdose deaths.
Hoffman is reported to have withdrawn a total of $1,200 (£735) in six visits to a cash machine the day before his death.