"Emmanuel was invited over for talks last Wednesday but he arrived a day early whilst our team were preparing for a pre season friendly against Exeter," Bruce told the club's official website.
"Our reserve team coach Keith Bertschin collected him from Birmingham airport in my absence.
"The following day he undertook a medical which he failed when the results showed a number of serious medical issues.
"We therefore felt it would be too risky to pursue the player with a transfer deal of this size.
"Following his disparaging comments that have been reported over the last 48 hours, we feel that it is only right that Blues fans should be made aware of the true reasons for the collapse of the transfer.
We are very disappointed with the way the club has been portrayed, particularly as the club has an excellent track record of looking after potential signings."