A teenager found dead in Woodford Green has been named as 18 year-old Luke Harwood from Havering.
His body was discovered by police near Broadmead Fields on Monday night.
Four men and a woman, who were arrested in connection with his death, are being interviewed by police.
A post-mortem examination is expected to take place today.
Police are particularly interested in hearing from anyone who saw a blue Fiat Punto in Courtland Close - or activity near the bridge in Chigwell Road (close to the Jet petrol station) - on Sunday or Monday.
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The high of 35C was recorded on a Bakerloo line train between Piccadilly Circus and Oxford Circus at 2pm.
Weather forecasters say temperatures could reach 35C, beating the previous record of 34.6C in the scorching summer of 1976.
After years of political manoeuvring over the future expansion of Heathrow Airport, there has been an important development this lunchtime.