The German club had sworn when the forward joined Arsenal that his No.10 would remain unused as long as he continued to play professionally but have given it to Patrick Helmes
The Germany international's boyhood team, where he rose through the ranks and played either side of a transfer to Bayern Munich, had told him when he left for Arsenal in 2012 that nobody else would wear his number as long as he continued to play professionally.
|WORLD CUP LATEST
|3/1||Lukas Podolski is 3/1 with William Hill to score against Brazil|
He told Express: "Lukas was informed about it right in the middle of his preparations for the World Cup quarter-finals. We are surprised, to say the least, that this promise has been broken - and in such an impersonal manner.
"It is a strange decision but Lukas's attitude towards Koln will not change despite this empty promise."
Koln president Werner Spinner admits that the club had gone against their word but stressed that he had to consider the club as a whole rather than one player.
"We gave Lukas our word," he conceded. "But I wrote him a letter asking for his understanding.
"If the sporting directors, big parts of the team and a large part of our fans have this wish [for Helmes to wear No.10], I will submit to it. I always think about the whole club and not individuals."