Liam Payne's 'erratic behavior' began after Kate Cassidy left from Argentina

Liam Payne's behaviour reportedly became more erratic after his girlfriend Kate Cassidy left from their vacation in Argentina.

According to a report by PEOPLE magazine, insiders have claimed that the late One Direction member was a completely different person around Kate.

A source told the outlet, ""Like you could see from the Snapchat videos, he was a different person around her."

They added that Kate "had been super supportive of him through all the legal drama and very much stood by him" referring to Liam's recent legal struggles with ex-fiancee Maya Henry.

Liam passed away on Wednesday at the age of 31 after falling down from the balcony of his room at the CasaSur Palermo Hotel in Buenos Aires, Argentina.

Several outlets have reported that autopsy results have now revealed that Liam had several drugs in his body at the time of his death.

Additionally, the outlet also revealed that the autopsy results explained that "the head injuries were sufficient to cause death." 

However, the "internal and external hemorrhages" of the skull, thorax, abdomen and limbs contributed to the singer's tragic death.