Did IRS hold SEC back from investigating Madoff?

Madoff investors were dutifully paying taxes to the IRS on all his faux trades based on his reporting to them & the IRS.

The investor's were royally screwed. Madoff lived high off the obese & sweating hog for years but will now, at least personally, pay the hog's reaper but someone has made out just FINE through all of this.

Yup. The IRS was taking in all those taxes. Will those monies be returned to the investors?

Is it really possible that the IRS had no idea these taxes were based on delusional criminality?

Think on that.