Premier League high-flyers Manchester City paid a record 175,000 pounds ($215,000) to sign 13-year-old defender Finley Burns from third-tier Southend United last week, the Times reported on Friday.
The newspaper said the overall cost of the transfer could rise to more than 250,000 pounds if Burns goes on to sign professional terms at the Abu Dhabi-owned club.
No fee or details about subsequent payments were given by either club at the time of Burns's signing.
The Times said City's outlay was unprecedented for a 13-year-old, with the club paying almost 150,000 more than they were obliged to under the Elite Player Performance Plan (EPPP).
The plan governs the compensation given to clubs who lose academy players.
"There were four or five Premier League clubs after Finley in the end and it's extremely difficult to keep hold of a boy once that's happens," Southend's head of youth football Ricky Duncan said last week.
"He would have had a 10-day window of opportunity to look elsewhere at the end of the season so this was the best way to do it. He's a great kid from a nice family and everything was sorted out amicably which is how it should be."
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City have paid big sums on young players in the past, spending a reported 200,000 pounds for Spanish youth player Brahim Diaz in 2013 and 500,000 pounds on winger Jadon Sancho in 2015.
Both players were 14 at the time of their transfers