According to report in his native Denmark last week, Ceylan had tested positive for and admitted cocaine use.
The 28 year-old was due to fight Galahad in London next month on the Chris Eubank Jr. v Arthur Abraham bill and was tested out of competition following his EBU title defence against Isaac Lowe last March.
Ceylan’s notified the European Boxing Union two weeks ago of his desire to leave the championship behind before this latest revelation was made public by the fighter himself.
The Sauerland promoted boxer told bt.dk: “It was a mistake and a moment of weakness, I am deeply sorry. This was the first and only time in my life I have taken drugs and I promise it will be the last.
“From a young age and throughout my life I have experienced first-hand the devastating effects that drugs can have on people’s lives. I lost my mother to drugs and have seen many of my friends and family follow a similar path.”
As the test failure was not in the run up to a fight, the Danish Boxing Federation are not said to planning a ban for Ceylan, although the British Board have now acted to block the contest.
A fringe version of the IBF featherweight crown was due to be on the line, although Galahad will get a new opponent.
Former opponent Lowe (with whom he scored a techinical draw against) gave his opinion on the saga in the aftermath and had called for action to be taken.
“It’s just one of them though isn’t it, most boxers and athletes do it, it is what it is but I think it’s hard for myself and other boxers who do everything by the book and when it’s a big fight like it was,” Lowe exclusively told World Boxing News.
“I go to his back garden for the biggest fight of my life and then it’s revealed he’s been on drugs. It’s cheating the sport and it’s a shame. As long as his health is alright that’s the main thing.
“I’m going to make a compliant (to the board) I went over there in his backyard, done everything by the book so of course I’m going to complain, you’re not a boxing fan or a right person if you think I don’t deserve another chance for the title.
“I was getting into the fight and about to take over before it got took away from me but to find out he’s been on drugs, I definitely think there should be something done about it.”
Galahad’s replacement will be announced in due course.
Phil Jay is Editor of World Boxing News. Follow on Twitter @PhilDJay