The Dutch midfielder was set to join the Black Cats on a season-long loan.
The report cites ‘sources from the capital’ as revealing the turn of the events and it is believed that the 25-year old has now returned to QPR.
The powerful midfielder has previous in this area – failing his medical at Everton when a move looked to be complete back in 2013 – and it’s the second Sunderland deal to be scuppered at the medical stage this summer.
Belgian defender Nicolas Lombaerts was all set to finalise a move before issues with his medical saw that deal collapse, frustrating Dick Advocaat in his attempts to rebuild the Sunderland squad.
While some solid defensive acquisitions have been made at the Stadium of Light – most notably Younes Kaboul – Jeremain Lens remains the only real top quality arrival and Sunderland will need to add more before the transfer window closes.
Former French international Yann M’Vila has arrived on Wearside ahead of completing a move - again reported by the Sunderland Echo - and getting that deal over the line is even more crucial in the light of the Fer revelations.