Anojan Gnaneswaran was found injured at Strawberry Hill station just after 11.50pm on January 8.
The 21-year-old was pronounced dead at the scene shortly after.
Anojan’s family have since paid tribute to their “much-loved” son and brother who was excited for his future.
They said: “Anojan was a much-loved son and brother, and we are devastated that his young life has been ended in this way.
“He was in his third year at university studying accounting and finance and he was so excited for his future.
“He excelled at all sports and had achieved first-dan black belt in karate – he competed in the World and European championships in karate, and we will all miss him so much.”
Two men, aged 19, and a 17-year-old boy, were arrested on January 12 in connection with the investigation.
Previously, two men, aged 19 and 20, and a 15-year-old boy were also arrested in connection with the incident.
They have been released under investigation.
A 16-year-old boy was also arrested but has been released on police bail.
On the same day, a 16-year-old boy was also found injured after a stabbing in Alexander Close, Twickenham.
This is the same 16-year-old who was arrested.
Officers and London Ambulance Service crews attended and found a boy with a slash in his leg.
His condition was assessed as not life-threatening.
Police are treating the two incidents as related.
Senior investigating officer Detective Inspector Paul Attwell said: “My thoughts are with Mr Gnaneswaran’s family and loved ones at such a difficult time.
“I know will this loss impact the wider community and I would like to reassure them our investigation continues at pace.
“I urge anyone with information that hasn’t been in touch already to reach out as soon as possible, by texting 61016 or calling 0800 405040 quoting reference 630 of 08/01/24, or via this link.
“Alternatively, you can call Crimestoppers anonymously on 0800 555 111.”