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.