Bellamy signed a four-year deal with former Wales boss Mark Hughes on Thursday, ending his troubled time on Tyneside.
This revelation means that Steve Bruce has twice had an offer accepted for the 25-year old, and twice been rejected by the player.
The statement by Birmingham said: "Birmingham City can confirm they had an offer of 5m accepted by Newcastle for striker Craig Bellamy."
Despite concerns by some over Bellamy's reputation, Hughes has waved it off saying:
"I am not bothered about Craig's reputation.
"It is not about what has gone on before, it is what happens in the future.
"I am not privy to those past details anyway. All I know is that Craig is a fantastic player.
"He strives to be the best he can be and he has a platform at Blackburn now to show what he is all about."
Bellamy spent the second half of last season on loan at Scottish side Celtic following his fall out with Newcastle boss Graeme Souness.