A teenager from Thornton Heath has been arrested on suspicion of violent disorder in connection with the murder investigation of 17-year-old Kyall Parnell in Tulse Hill.

Kyall was stabbed in the heart in Norwood Road near the junction with Station Rise at about 10.43pm on New Year’s Eve.

Police arrested the 16-year-old along with another boy from Lambeth of the same age – the second on suspicion of murder – on Thursday, January 4.

They are both currently in custody in south London police stations.

Despite police and London’s Air Ambulance attending, Kyall was pronounced dead at the scene at 11.38pm.

A post-mortem examination, performed on Tuesday, January 2, gave Kyall’s cause of death as the stab-wound to the heart.

Police are still unsure of the motive, although they believe an initial altercation might have begun on a 68 bus travelling towards Herne Hill shortly before the stabbing.

DI Ian Titterrell, said: "Kyall was only 17 and his death has devastated his family and those who knew him. We have made two arrests but we are continuing to investigate the circumstances surrounding Kyall’s death. We would urge anyone with information about what happened to contact police."

Anyone with information is asked to call the Met Police incident room on 020 8721 4005, or contact them through Twitter @MetCC.

Alternatively, to remain anonymous, call Crimestoppers on 0800 555 111.