Police have confirmed that an 18-year-old man from Southampton has died on Sunday 18th August at Southampton General Hospital.
The man's next-of-kin have been informed but the man can not be identified until all procedures have been completed.
A post-mortem examination will be held later this week to establish the cause of death.
Superintendent Ben Snuggs said: "This is a very sad time for this young man’s family and our thoughts and condolences are with them."
This tragic death shows how important it is that people realise the dangers associated with taking ‘legal highs.’ They are not necessarily safe and sometimes have been shown to contain potentially lethal substances.
This is the third extremely serious case involving AMT in Hampshire since last year. I would therefore urge people who are considering taking any type of non-personally prescribed drug to think very carefully about the potential consequences.”