Mayweather came out of retirement for the much hyped fight against UFC’s biggest star Conor McGregor at the T-Mobile arena in Las Vegas.
After much build-up, Mayweather beat McGregor in the tenth round through a TKO decision on Saturday night.
He improved his overall career record to a staggering 50 wins and zero losses.
Research conducted exclusively for Express.co.uk that was published over the weekend suggested more than eight million Brits planned to watch the McGregor vs Mayweather fight.
And of those, some three million intended to watch the fight illegally online.
Those fans, who watched the fight using illegal add-ons for Kodi or through illegal live streams, have now been put on alert.
During the fight a number of viewers who live streamed it illegally reported seeing a mysterious code appear on screen.
The unusual watermark raised suspicions that someone was trying to figure out which users were breaking piracy laws to illegally stream the event.
TorrentFreak reported that a source had made the unsubstantiated claim to them that the code had originated from a legal broadcast.
Two other users also reported seeing the codes, which were a letter and number combination that briefly appeared.
They appeared in 20 to 23 sets of pairs, and stayed the same throughout the broadcast.
The codes reportedly did not appear when the main action was taking place, but only when the camera turned to each corner of the ring.
TorrentFreak said: “Since no digits appeared over the top of the fight itself, it might suggest that they were put there by a broadcaster who were licensed to show the fight.”
They theorised that these codes would allow the broadcaster to track any “illicit stream back to a subscriber and/or a set-top box tied to a particular account.”
They added: “Since that subscriber has then re-streamed that content back online illegally, the code would act as a homing beacon and could spell bad news for the individual involved.”
TorrentFreak also published images showing the code appearing on screen during the fight, with it redacted sightly to protect the identity of the person who provided the picture.
It’s also possible that the watermark was simply added by someone who deals with illegal live streams to keep tabs on where the stream was being distributed.
If it was added by broadcasters to track down…