Police have made an urgent appeal to drug users about a "bad batch" of heroin, after one man died from a suspected overdose and another is in critical condition in hospital.

Two men, suspected of overdosing on the drug, were found at different places in east London yesterday.

A 20-year-old man was found about 8am at a house in North Street, E13. He was pronounced dead at the scene. Police found a syringe near his body. A post mortem will be held in due course.

About 12 hours later a 30-year-old man was found unconscious in Fern Road, E15 with a syringe lying near his body. He was taken to an east London hospital where he remains in a critical condition.

"Substances found at both locations have yet to be analysed, but officers have reason to believe the substance used in both cases was heroin," a Scotland Yard spokesman said.

Anyone with any information relating to either incident is asked to contact Newham police station on 020 7217 5221 or Crimestoppers on 0800 555 111.