The Football Association has asked betting companies to provide any relevant information relating to John Terry's substitution after 26 minutes of his farewell Chelsea appearance against Sunderland on Sunday.
The 36-year-old captain was given a guard of honour by his fellow players as he departed in a pre-planned substitution - timed for the minute matching the shirt number he has worn across 717 appearances for the newly crowned Premier League champions.
However, amid reports that some punters won sizable sums of money by putting on bets that Terry would make way at that stage of the eventual 5-1 victory, the FA has asked bookmakers for their observations.
The timing of the substitution was Terry's idea and he told Sky Sports after the match that he had to persuade Antonio Conte over his scheme.
"I had a discussion with the manager – I think he wanted to get the boys that didn't play on Monday night against Watford and give them a run out," he said.
"So I kind of negotiated with him to play 26 minutes and come off. It was a compromise between the two of us."
Conte hailed Terry as a "legend of this club" after the match, while his now departed Sunderland counterpart David Moyes confirmed his side agreed to put the ball out so Gary Cahill could come on in place of the former England skipper at the pre-arranged time.