World football's governing body FIFA has confirmed that they are investigating the transfer of Bruno Fernandes from Sporting to Manchester United.
The Premier League club signed the midfielder from the Portuguese top-flight side last January, for an initial fee of €55m with potential add-ons totalling €25m.
There is no indication that Manchester United are liable for any of the money but his former club Sampdoria have lodged a complaint with FIFA, claiming that they are owed a 10 per cent sell-on clause.
The Serie A club, for whom he made 33 league appearances in one season, sold the Portugal international to Sporting in the summer of 2017 for a fee of €8.5m plus add-ons.
A FIFA spokesperson said: "We can confirm that on April 3, 2020 the Italian club, Sampdoria, lodged a claim with FIFA against the Portuguese club, Sporting Clube de Portugal, related to financial obligations set out in the contract corresponding to the transfer of the Portuguese player, Bruno Fernandes.
"The matter is currently being investigated and consequently we cannot provide further comments."
If the Italian club are successful in their claim, they could be owed at least €5.5m from Sporting.
Fernandes has made a big impact since signing his five-and-a-half year deal at Old Trafford.
The 25-year-old was voted the Premier League’s Player of the Month for February after he registered a goal and two assists in helping United to two wins and a draw that month.
Before the season was cut short, he scored the equaliser in a draw with Everton before setting up Anthony Martial for the opening goal in a crucial Manchester derby victory.
Fernandes was reluctant to be showered with individual praise: "We can talk about a new start after Bruno but it is not about Bruno, it is about the team. One player doesn't change a team.
"The team changes when everyone pushes together for the same side."
