An inquest examining the deaths of five music festival revellers in recent months could see the addition of two more young people who died in similar circumstances.

A directions hearing before the NSW Coroners Court on Tuesday morning heard that one festival attendee who died of a suspected drug overdose between September and January had consumed up to nine ecstasy pills, of 77 per cent MDMA purity, throughout the course of the day.

Alex Ross-King, 19, who died of a suspected drug overdose after attending FOMO music festival in Parramatta on January 12.

Counsel assisting the Coroner, Peggy Dwyer, said that in contrast one of the young adults died after only consuming one tablet.

Dr Dwyer said one person who died was drinking alcohol while also consuming MDMA, while others did not drink alcohol.