The cause of Matthew Perry’s death is unknown and has been “deferred” pending further investigation.

The Friends actor was found unresponsive in a hot tub at his house on Saturday and police told CBS News that there were no obvious signs of trauma.

Perry’s post-mortem examination was inconclusive, and the LA County Medical Examiner’s office updated their file on Sunday to say the case had been deferred.

BBC News reports that this usually means that the post-mortem is complete but more detail is needed.

Perry, who died at the age of 54, was best known for playing Chandler Bing in 90s TV sitcom Friends which followed six young friends living in New York City.

The show aired from 1994 until 2004 and its final episode was watched by 52.5 million in the US, making it the most watched TV episode of the 2000s.