Vietnamese police on Monday put the takings from a bond scam at real estate developer Van Thinh Phat Holdings Group and its affiliates at around US$1.23 billion (about RM5.8 billion).
The companies cheated around 42,000 investors, the Ministry of Public Security said in a statement.
This is the first time Vietnamese authorities have announced the amount of money involved in the case since they arrested the chairwoman of the company, Truong My Lan, a year ago on suspicion of financial fraud.
No one has yet gone on trial. The company has not made a public comment on the accusations. Reuters could not immediately reach Lan's lawyers for comment.
Van Thinh Phat and its affiliates were accused of illegally issuing bonds to raise money from the investors from 2018-2020.
The ministry said it had asked the victims to work with the investigators "to complete the investigation and protect their right".
Vietnam recently broadened its anti-graft drive with a series of high-profile corporate arrests, including top stockbrokers, property developers and even regulators.