As far as he is not using this money for his own personal gain I don't think he is stealing, since he is returning the money for a foundation for the use of the masses he is doing the needful because the public fund belongs to the citizens.
The man is in a situation whereby he can't reject the money and with his political office he can't fight the corruption because it is beyond his power , so I think the best thing is to channel the money to the public because money from government is for governance and it belongs to the people. He already has evidence of what to show the public what the money was done with, he is better than others who channel this money to their own personal self.
I remember someone said to me like this "if you didn't stop someone from doing bad or illegal thing, it means you're supporting the bad or illegal thing". He's working in officials, he do can fight against corruption if he want, "fight" isn't always have a power to fire or change the employee, but you do can fight by complain the bad thing and encourage them to stop it.
Regardless the way he use the money, if he did wrong, he's still wrong.
It is true that if one does not commit corruption but for some reason he has to accept the money of corruption then he is definitely liable there. Actually I do not include any bad work but if I receive a part of the money from that work then I myself am equally guilty there. If I confess my weakness here and enjoy that money or use it for some other purpose, there will be an equal crime. So if you see any corruption, it is better to protest there. But one more thing everyone should think that even if it is for the sake of saving life or job, corruption has to be done, otherwise there is a risk of life being endangered sometimes, there is no justification for not accepting the money of corruption. No one can do anything in this case. I think if he uses that money for some good cause then there is no way to blame him.