Lazio wing-back Jordan Lukaku had been all set to join Newcastle United, but the transfer has officially collapsed.
The younger brother of Manchester United striker Romelu Lukaku was expected to make the move to the Premier League.
“Newcastle United can confirm that Jordan Lukaku will not be joining the club,” read a statement.
“The Belgian defender was on Tyneside on Friday after being given permission to travel by his current club, SS Lazio.
“It has now been decided that a loan deal will not be pursued and the player will return to Rome.”
FIFA agent Vincenzo Morabito suggested on Facebook that the issue was medical. "I think they might send him back..."
However, Sky Sport Italia insist it was a discussion over how his salary would be divided up between the clubs.
The 24-year-old made eight competitive appearances for Lazio this season, providing one assist, but only returned in November after five months out.
He had muscular problems, then the inflammation of knee ligaments.