A man who died following an argument in a popular late-night hotspot has been described as "well loved and hugely popular" by his family.
Tommy Blackmore, 20, was a prolific fundraiser whose efforts helped the Fight 4 Cancer campaign to raise £32,000 for Cancer Research UK.
More than 150 family and friends of the lifelong Millwall fan walked to Tower Bridge, the spot where he was found by emergency services, to pay their respects today.
In a statement, relatives said: "He was a loving and fiercely loyal son, brother, uncle and friend.
"He made an impact on and had time for everybody who crossed his path. A vibrant character, cheeky, charming, comical and wise way beyond his 20 years."
Two men, aged 24 and 28, have been arrested on suspicion of murder following the incident early yesterday morning.
Officers were called at around 2.35am to reports of a disturbance in Queen Elizabeth Street in central London.
They found the victim with critical injuries and he was taken to hospital, where he was pronounced dead at 3.45am.
Another two men were arrested for GBH and have been bailed until mid-June.
Tributes have poured in for the victim and the family said boats on the River Thames flew their flags at half-mast as a sign of respect.
Their statement continued: "He was a well loved and hugely popular boy, which has been demonstrated by the sheer number of people who have left a sea of flowers and tributes, both at his family home and at Tower Bridge.
"Tommy has been summed up by the thousands of comments left on social media in the last 36 hours which have all been positive and described him as the harmless and fun character that he was.
"The respect and love that has been shown is usually reserved for someone much older and is a testament to what a terrible loss has been suffered."
Detective Chief Inspector Rebecca Reeves said: "Although we are in the early stages of the investigation we believe that an argument involving a number of men and women took place in Tower Bridge Road.
"This then continued in Queen Elizabeth Street where the victim subsequently died.
"The area around Tooley Street has a popular nightlife and I would ask that anyone who had been to a club in the area and may have witnessed the assault to contact us.
"A number of night buses also use this route and it is possible that someone travelling to work, or heading home, may have seen something that will assist our investigation."
Anyone with information is asked to contact the police incident room on 020 8721 4868, or Crimestoppers, anonymously, on 0800 555 111.