TAIPEI (AFP) - Taiwanese prosecutors said on Thursday they have launched an investigation into alleged wrongdoing by fund managers at two securities firms that caused massive losses to a government fund.

Prosecutors on Wednesday raided the firms and questioned eight people on suspicion of insider trading, manipulation of stock prices and breach of trust from 2010-2012, they said in a statement.

The suspects actions allegedly resulted in more than NT$1 billion (S$41 million) in losses to the government while allowing them to make illegal profits of nearly NT$100 million on the stock market.

Taiwan's financial regulators started reviewing 13 securities firms trusted with handling government investment funds after a similar case surfaced late last year.