Malaysian state-run fund 1Malaysia Development Berhad was involved in “a Ponzi scheme,” a Swiss prosecutor said Wednesday. Switzerland has also widened its investigation into 1MDB’s alleged corruption scandal

The Swiss attorney general’s office had “identified further suspect transactions involving the Swiss financial sector,” it said in a statement.

“Firstly, the sum of $800 million appears to have been misappropriated from investments in natural resources made by the SRC sovereign fund [Malaysian company]. Secondly, it is suspected that a ‘Ponzi‘ scheme fraud (i.e. paying the returns on initial investments from funds obtained from subsequent investors rather than from legitimate revenue from the investments) was committed to conceal the misappropriations from both the SRC fund and from 1MDB,” the statement further read.

The Swiss investigation into 1MDB’s alleged fraud was launched last August after allegations said that some of the money siphoned off from the Malaysian fund passed through Swiss banks. Four people and a bank are under scrutiny in Switzerland following the investigation.

Set up by Malaysian Prime Minister Najib Razak, 1MDB has been at the center of corruption scandal after a Wall Street Journal report that said $681 million was traced back to back accounts allegedly owned by Najib. He has denied of any wrongdoing.