Thames Valley Police are re-investigating the deaths of eight people dating back to the 1970s.
Cold case detectives say the deaths - which occured in Berkshire, Oxfordshire, and Buckinghamshire - are unrelated.
The operation, named Nightingale, has been established as police have previously been unable to identify the bodies in each case.
More top news
A number of teenagers, aged 13 to 15, from Portsmouth, have been treated in hospital, after taking tablets believed to be diazepam.
Thursday Evening's Pollen Forecast
Thursday night's weather for the east of the region