A teenager who is believed to have taken so-called "laughing gas" at a party in south-east London has died.

The 18-year-old was taken to hospital after collapsing in a street in Bexleyheath late on Saturday night. He died two hours later.

The Metropolitan Police said he was believed to have been drinking alcohol as well as ingesting the legal high nitrous oxide, also known as laughing gas.

However, police are treating the death as unexplained.

Jean MacKenzie reports.