A 25-year-old man stabbed to death in an alleyway in north London in the early hours of Saturday morning has been named as Wilham Mendes, a Portuguese amateur boxer.

Mendes, 25, was found by police and paramedics in Tottenham at about 1.20am on Saturday. He had been repeatedly stabbed. He was taken to an east London hospital, where he was pronounced dead less than an hour later.

Mendes, who lived in Tottenham, had moved to the UK in 2015. He was a keen boxer and had recently won an amateur bout, a relative said.

His identity was only revealed after an appeal by police, who initially were unable to determine who he was or how to contact his family. His next of kin have been informed, but formal identification and a postmortem examination are yet to take place.

On Sunday, police arrested two boys aged 15 and 16 on suspicion of murder. They remained in custody in north London police stations on Monday.

DCI Glen Lloyd, who is leading the investigation by the Metropolitan police’s homicide and major crime command, said: “Although we have made two arrests, our investigation continues to gather pace.

“Early inquiries by my team have established a possibility that Wilham was stabbed during a robbery, and I would like anyone who saw the events leading up to or immediately following the murder to contact my officers without delay.

“No matter how small a detail, no matter how little you saw, your information could prove vital to our investigation and at the very least, would assist in confirming details that we already have.

“At the heart of our investigation is the loss of an innocent and promising young man who was brutally murdered in the street.

“Our thoughts are with Wilham’s family as they struggle to cope with their loss at what should have been a happy time of year for them.”