Credit Suisse Group AG, JSC VTB Bank and BNP Paribas SA are embroiled in an investigation by the U.S. Securities and Exchange Commission into the sale of $850 million in bonds issued by Mozambique, The Wall Street Journal reported Dec. 28.

The bonds were sold by the three lenders in 2013 to investors for a Mozambican state-owned company that needed money for tuna fishing. However, the government later said it also used the funds to purchase military equipment, the Journal noted.

There was also $1.2 billion in undisclosed loans from Credit Suisse and VTB to other state-owned companies for additional military purchases.

The SEC wrote to bondholders in November asking them to hand over documents provided by the three banks in connection with the sale of the bonds, including all communications with the banks, the report added, citing a copy of the letter.

U.K. and Swiss regulators launched probes into Credit Suisse's and VTB Bank's involvement in Mozambique's debt in the summer, the Journal noted. The IMF and other donors in April suspended aid to Mozambique after discovering the undisclosed loans.

Mozambican President Filipe Nyusi recently agreed to an international audit of the country's debt deals in a bid to resume international aid, according to the report.

Mozambique told investors in 2015 that it intended to restructure the $850 million debt. In late October 2016, it announced that it needed to restructure its debt again, this time including the additional $1.2 billion in bank loans, but bondholders rejected the proposal.