City club stewards where beleived to have received a number of complaints from home supporters after the Senegalese ace had given the Wanderers the lead but evidence has proved inconclusive meaning that the matter will not be taken any further.
A statement today read
"Bolton Wanderers Football Club has been in contact with Birmingham City on Tuesday regarding the alleged spitting incident involving El-Hadji Diouf.
"Birmingham City have confirmed they have received no complaints and the stadium's CCTV system has no evidence of the allegation.
"Both clubs will not be taking further action and the matter is now closed."
Diouf has been playing some of the best football of his career during his time at the Reebok Stadium yet is often made a target of opposing supporters due to his character.
Previously the African had served a ban for spitting at Portsmouth's Arjan De Zeeuw and was investigated for a similar incident at Middlesbrough earlier on in the season.
It seems as if other clubs are just looking at ways in which they can get the striker into further trouble even when it is not justified. Something which chairman Phil Gartside is already aware of.
"The lad's being treated unfairly at the minute and anything he does is being examined,"
"He's become the nature of a lot of attention that is unnecessary. He's taken his punishment and he's now got to be given the chance to rebuild his career. He's also a very charming young man and I've got a lot of time for him personally."