A third teenager has been arrested on suspicion of murdering Matthew Kitandwe in Battersea.

Mr Kitandwe, 18, a promising footballer, was stabbed to death in the stairwell of a block of flats in Wayford Street on Tuesday, June 21.

A 17-year-old boy was arrested today and is being held in custody in a south London police station, the Metropolitan Police has said.

Mr Kitandwe’s family paid tribute to the former South Thames College pupil, describing him as “very popular” and “much loved by everyone”.

His mum Rose said: "My son Matthew, you will be greatly missed. You were my best friend and the house feels empty without you.

“It is a traumatic time for all the family. You were much loved by everyone and have left a very big gap to fill. We don’t want any other family to go through this."

Uncle James added: "Matthew was an excellent sportsman, who represented Wandsworth borough in athletics, Uganda U-17s in football and had recently been signed by Colliers Wood FC.

“He was very popular, creating enduring friendships with everyone he came across and cared deeply for friends and family.

“He was funny with a mischievous sense of humour and, curious to know more about his family’s background and culture, went to Uganda for 18 months. He is so greatly missed."

Police were first called to Wayford Street by paramedics at 4.16pm, to reports of a man having been stabbed.

Mr Kitandwe was pronounced dead at the scene at about 5pm.

Detectives have appealed for the first time for information about a group of young men seen standing by a small, light coloured vehicle parked outside the block of flats at about the time Mr Kitandwe was killed – 4pm.

At the same time, a black hatchback was seen to drive four times up and down Cabul Road, which adjoins Wayford Street.

One of the young men who had been standing outside the block of flats walked over to the black hatchback and got in before it drove off, police said.

Crimestoppers has offered a £10,000 reward to anyone with information on the stabbing.

DCI Sam Price, of the homicide and major crime command, said: "Two weeks on, we are still no nearer to finding a motive as to why Matthew was attacked.

“So far we have found no evidence to suggest that this young man was affiliated to gangs or to any other type of crime.”

Two other teenagers were arrested on suspicion of murder last month.

An 18-year-old man was arrested on Thursday, 23 June and a 16-year-old boy on Monday, June 27. They have been bailed until August and July respectively.

Anyone with information should call the incident room on 020 8721 5054, police on 101, or Crimestoppers anonymously on 0800 555 111.