Can uscis could request the documents they RFE before?

LCSilence

Registered Users (C)
My I485 is pending and recently I answered a RFE to USCIS. Due to retrogression my case may be pending for another couple of years. Could USCIS ask for the documents that I have submitted before?
 
I don't see why not. If they suspect there is something that needs to verify they surely will request RFE, such as employer letter, tax return, finger print etc.
 
I read some on this forum before, that USCIS could not requrest the same documents the RFEed before. Could anybody help me confirm this?

Thanks,
 
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