Suffolk Police have seized more than 400 of the lethal Superman ecstasy pills thought to have killed three men in Ipswich.
Officers discovered the cache of pills featuring the Superman logo stashed next to Norwich Road, near Ipswich town centre on Sunday night (4 January).
The force had offered an amnesty on the contaminated class A drug after two men, aged 22 and 24, from addresses in Ipswich, died on Christmas Eve and New Year's Day from suspected overdoses.
The death of a third man, aged 20, is also being investigated with detectives looking into a possible link to the batch, while a fourth man is recovering in hospital after taking the tablet.
Chief superintendent Jon Brighton from Suffolk Constabulary said: "This seizure is a significant development in our investigation into the supply of dangerous drugs which are believed to be linked to the tragic deaths of two young men in Ipswich.
"If these prove to be the same as those linked to these cases we will have gone a significant way towards reducing the risk of further serious injury or deaths linked to this particular ecstasy pill.
"We do not know however how many are still in circulation, so I continue to urge anyone in possession of these drugs to hand them in to police or partner agencies."
Adrian Lubecki, 19, of St Matthews Street in Ipswich, was charged with being concerned in the supply of controlled drugs (ecstasy) and possession with intent to supply a Class B drug.
He was been remanded in custody and appeared at Ipswich Magistrates Court this morning.
A 20-year-old man and a 26-year-old man from Ipswich, arrested on suspicion of being concerned in the supply of controlled drugs, have been released on police bail pending further investigation.