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 not as easy like you think, it all depends on the level of corruption in that state. If it is a state whereby the own system and every sector is corrupt and you found yourself not as a top government officials it won't be easy to fight this top politicians because they are majority and at this point you will be confused. I'm not justifying corruption or in support for people to do wrong thing.
If the power is not what you can't fight and if you don't want to partake in stealing, it is better to use that fund for the masses, there is nothing wrong with it and doing so I think it is beginning fight against corrupt practices. The essence of governance is for the people to feel the impact of leadership. Using money that is meant for the public it means you are not betraying the people which they can have hope in you over other corrupt leaders.