Barkley sealed a £15 million move to Chelsea last week, less than five months after he pulled out of an original £35m switch to the Premier League champions. The Liverpool-born midfielder needs game time but with N'Golo Kante, Tiemoue Bakayoko, Cesc Fabregas and Danny Drinkwater all vying for a place in the middle of the park, it will take hard work.
Tottenham were one of the clubs that was strongly linked with the England international during the past few months.
"I believe the circumstance of his transfer now warrants serious investigation", the Liverpool mayor was quoted as writing in the letter by the Guardian.
The Italian boss has signalled that making the World Cup should be a motivational factor for Ross Barkley in the remainder of this season.
The former Everton man will have a big ride in store, as he'll look to prove he can play in Antonio Conte's tactical system. In the worst case, it is the intention of lowering the player's transfer fee in the interests of the player, his agent, and the club that bought him.
That I say the 'primary' victim of any alleged 'fraud' is Everton is because there would be (assume for one moment that if this was not a fraudulent transaction it was a cynically and some might save cunningly structured transfer designed to benefit the few at the expense of the many) numerous secondary victims. Since 2013, recent FIFA data states that 1.59 billion USD has been paid to football intermediaries acting for clubs.
But perhaps the most startling point in the letter - and the passage that proves how seriously the mayor is taking this - comes when he suggests he has contacted the police over the issue.
"I am so concerned about the circumstances surrounding this transfer I am asking the appropriate police authorities to consider whether any fraud has taken place".
"As a politician - and someone who supports and rightly welcomes scrutiny under the Nolan Principles - I feel it is right that the public receive an assurance on this matter - and that transfers are monitored more closely".