A teenager and a 25-year-old man found dead in a Kent pond had alcohol and the drug methoxetamine in their bodies.
The bodies of 17-year-old Hugo Wenn and Daniel Lloyd were pulled from Reed Pond, near Tennyson Avenue, Canterbury on 30 January.
Toxicology tests showed that both had methoxetamine (MXE) and alcohol in their bodies at time of death.
Post-mortem examinations revealed they died from drowning and police are not treating their deaths as suspicious.
A 28-year-old man, who was arrested on suspicion of supplying controlled drugs following the deaths, has been released on police bail until 15 March.
Methoxetamine has similar effects to the banned drug ketamine and has been linked to the deaths of two people in Leicestershire.