While Eliaquim Mangala’s move to Manchester City may have, so far, not proved to be a success on the pitch, a report from Bloomberg says that FIFA have started to investigate the transfer over suspicions that Porto handed their negotiating power over to investment group Doyen Sports prior to the Frenchman’s big-money move to Eastlands in the summer of 2014.

Mangala has proved to be one of The Blues’ most expensive purchases of the Sheikh Mansour era, but has failed to replicate that on the pitch. He’s shown significant improvement this season, but injury have kept him out of the team in more recent times, being replaced in the side by Martin Demichelis and Nicolas Otamendi, with Vincent Kompany also being absent for a long period prior to the international break.

The fee Manchester City paid for the defender is quoted by Bloomberg as being €54 million, equivalent to £40.3 million, an amount which would have made Mangala the most expensive signing of City’s history at the time. This has now been surpassed by Raheem Sterling and Kevin De Bruyne both moving to The Blues for bigger fees in the summer just gone.

Now it appears Mangala’s move could be at the centre of another issue for FIFA in recent weeks, what with Sepp Blatter recently being suspended for 90 days. It’s alleged that Porto allowed control of the negotiating for Mangala to go to Doyen Sports rather than it remaining with the Portuguese side, which goes against the rules set in place by football’s governing body.

Bloomberg report that a FIFA spokesperson has said that the matter is being looked into, while all of Doyen Sports’ CEO, Vicky Kloss (a spokeswoman for the Premier League side) and Porto declined to comment on the matter at this stage, although they also say that Manchester City are not being investigated for any wrongdoing, and it’s just their Portuguese sellers that are being scrutinised.

The punishment for Porto could include a transfer ban not dissimilar to the one which has befallen Barcelona over recent transfer windows, or a fine.