Property developer John Chow says he and brother Michael have been treated like "two naughty school kids" in their suspension from the National Business Review rich list.
The Chow brothers are in charge of a substantial business portfolio including commercial properties, strip clubs and brothels.
In last year's rich list, the pair was said by NBR to be worth $170 million.
But NBR says it suspended them from the list this year "pending further investigation" after the brothers delisted their Chow Group.
"Property and finance remain John and Michael Chow's core business. However, their plans to take NZAX-listed Chow Group private has led to NBR taking a closer look at their privately held assets and their membership has been suspended pending further investigation," NBR said.