Forensic tests on batch of ecstasy pills seized in Ipswich reveal they do contain a dangerous ingredient.

More than 400 red triangle-shaped pills with a Superman logo were found in a public place near Norwich Road on Sunday.

It is believed this type of drug could be linked to the deaths of three men in Suffolk – two in Ipswich and one in Rendlesham – as well as others elsewhere in the UK.

Testing on the drugs has revealed they contain PMMA, a stronger and more dangerous active ingredient than those usually found in ecstasy.

Alan Murray, Suffolk county councillor for health, said: “These pills contain potentially lethal ingredients which as we have seen can have tragic consequences. We would urge people under no circumstances to take these or any other illegal drugs.

“This is a slow release drug taking several hours to work, and then lasting for several hours. Symptoms include initial shaking and sweating, which can develop into a rapid temperature increase, severely raised heart rate and blood pressure. When combined with alcohol or dehydration, this can prove fatal.

“If you have taken illegal drugs, or if you know someone who has become unwell after taking illegal drugs and needs urgent medical care, call 999 immediately and ask for the ambulance service.”

Police are investigating the deaths, as well as other cases which have left people seriously ill in hospital.

One man has been in court charged with being concerned in the supply of ecstasy, and has been remanded in custody to appear at Ipswich Crown Court next week, while two others are on bail pending further investigations.

Anyone in possession of the pills is urged not to take them, and to hand them in to prevent further deaths or harm.

Superintendent Louisa Pepper at Suffolk Constabulary said: “Our absolute priority is to prevent anyone else from suffering the tragic consequences of these drugs, by removing them from our communities.

“We’re urging anyone who has tablets matching this description not to take them or pass them on, and to hand them in to us or one of the agencies listed.

“We successfully seized a large quantity of drugs at the weekend but there may still be some out there so if you are offered them or have any information about these tablets, please contact us immediately.”

To date none of the drugs described have been handed in to police or partners.

Anyone in possession of the drug is asked to surrender it to police, in person or by calling 101, or at:

• CRI, St Matthews Street, Ipswich

• MVA Team, 70-74 St Helens Street, Ipswich

• Princes Street Fire Station, Ipswich

Anyone with information about the supply of illegal drugs should call police on 101 or Crimestoppers anonymously on 0800 555 111.