Met Police have apologised to the family of a teenage boy after a press release was issued to the media suggesting his death was connected to laughing gas.

Alistair Calvert, 18, from Sidcup, died in hospital in the early hours of Sunday July 26 after he collapsed in Wolvercote Road, Thamesmead.

Met Police initially inferred his death was connected to the use of nitrous oxide, also known as laughing gas, and alcohol.

During a radio interview discussing laughing gas and whether it should be outlawed, Met Police Commissioner Bernard Hogan-Howe referred to Alistair’s death as a ‘terrible outcome’.

A post-mortem examination held at Farnborough's Princess Royal University Hospital on July 28 concluded the teen died of natural causes.

In a statement issued today (September 23), Alistair’s family said: “Following the recent death of our son, grandson and brother Alistair Calvert, known as Ally to his family and friends, we would like to express our sincere gratitude for the love and support that we have received since his sudden passing.

"As a family, we have always been aware that Alistair did not take nitrous oxide nor excessive alcohol at a party on the night that he died.

“We were also advised, following his post mortem examination, that his death was due to an un-diagnosed significantly enlarged heart which caused sudden arrhythmia death syndrome.

“Any reference that Alistair's death was due to nitrous oxide is completely false.”

Since Alistair’s death, family and friends have raised almost £8,000 for the charity Cardiac Risk in the Young through a memorial and campaign ‘Ally’s Big Heart’.

The family say they have met with Bexley borough commander, Chief Superintendent Jeff Boothe and Sir Bernard, who have both apologised for the error.

Sir Bernard said:"I was incredibly moved when meeting Alistair's family last week during which they told me about their positive involvement with cardiac awareness since Alistair's death.

“This is a testament to their strength of character at a very difficult time.

“On behalf of The Met I extended my condolences to the family and apologised for upset caused by the statements we made about Alistair's death.

“I have apologised personally for the comments I made which inferred Alistair's tragic death was linked to the use of nitrous oxide and alcohol. “

Chief Supt Boothe said: “Any suggestion that Alistair’s death was in any way connected with the use of alcohol or nitrous oxide is completely false.

“Our thoughts and prayers are with his family at this difficult time.

"Our initial statement issued to media inferred that this death may have been connected with the ingestion of nitrous oxide and alcohol; this has been proven to be false and I have apologised to the family for the distress this statement has caused."

He added: “No inaccurate coverage should be allowed to tarnish the memory of Alistair.

“He deserves to be remembered for the fine, upstanding member of the community that he was."