Police have warned drug users about a possible contaminated batch of heroin after two deaths in three days. Both those who died were believed to be heroin users and lived only a few miles apart, Surrey Police said.
Samantha Johnson, a 28-year-old mother-of-two, collapsed and died in Stanwell, Staines, on Sunday.
She had a six-year-old son and a 10-year-old daughter.
On Tuesday, a man in his late 20s was found dead a few miles away in Wraysbury, Berkshire.
He has not yet been named by Thames Valley Police.
Surrey Police believe both victims probably used contaminated heroin from the same source.
Anyone who suffers unusual symptoms after taking the drug should immediately go to hospital for medical help.
Detective Chief Inspector Brian Marjoram said: "Our main concern is that if the supply of this batch of heroin goes unchecked it could result in further tragic deaths.
"I would ask anyone with any information that might help to contact us as a matter of urgency."