Police are investigating four deaths in two days believed to be linked to illegal drugs.
The inquiry follows the deaths of a woman and three men in south Essex on Monday and Tuesday.
Detective chief inspector Stephen Jennings, from Kent and Essex Serious Crime Directorate, said an investigation is under way to find out whether they are linked.
“We remain open-minded about that possibility and our inquiries are ongoing,” he said.
“We believe the deaths are all related to the taking of illicit drugs.
“I would urge people not take any illegal substances at any time but particularly not at this time.”
On Monday a man in his 20s was found dead at an address in Leigh-on-Sea and a woman in her 30s died in Westcliff.
The following day a man in his 40s died at an address in Canvey Island and a man in his 20s was found dead in Benfleet.
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