The closest I've seen is legislation that is worded to the effect "notwithstanding any other provisions of this section, this does not give the Department of Foo the authority to prosecute crimes covered under (b) above where the estimated damage is less than $5,000".
Basically it's a "we told you to do this generic thing, but that doesn't mean this is included in that".
That is "as close to" as an apple is close to an orange. Yes there are legislative carve outs for a myriad of reasons. I am suggesting that a complete bar against criminal investigations due to civil rights concerns is not one of them.
Basically it's a "we told you to do this generic thing, but that doesn't mean this is included in that".