Always worth reading: The World's Largest Hedge Fund is a Fraud [PDF] Nov 7, 2005 Submission to the SEC - Harry Markopolos https://www.math.nyu.edu/faculty/avellane/madoffmarkopoulos....
What happened to his General Electric fraud allegations?
On the other hand, there were some conflict of interest issues - I am not sure what the exact issue was.
But on the whole, the issue seems to have disappeared with the great Covid bust-boom of the stock market.