Background is simply that South Korean Exchanges Bithum and Upbit came under investigation from the South Korean Authorities. This probably triggered a fall in price as Bitcoin lost it's momentum and fell from almost $10,000 to as low as $8200.
The issue however, has never been fraud or whitewashing allegations. That has been mere speculation. For Upbit, it was solved yesterday. Upbit was trading yesterday without any problems. If there were any fraudulent activiy going on they would have been forced to suspend all services almost immediately.
Bithumb is still up and trading as well, tweeting about adding coins etc. This is a NO case, because what is going on is government trying to understand and "investigate" how exchanges are sharing liquidity of cryptos with other exchanges. This is very common, as pooling resources maximizes liquidity for all trading platforms involved.