Russia paid a coupon due on ruble bonds on Wednesday, but it's not clear how foreigners will be able to access the cash after the central bank banned transfers to foreign investors.

Investors are still scrambling to understand whether or not the bonds could be in default, even after the 11 billion ruble (US$98 million) payment that was widely expected. The Bank of Russia has introduced capital controls in a bid to avert a ruble collapse after its foreign reserves were frozen by international governments in response to Russia's invasion of Ukraine.

The restrictions could leave foreign investors, who held almost 3 trillion rubles ($29 billion) in the so-called OFZ debt at the start of February, unable to collect income on their holdings—which would raise the specter of the nation's first debt default since 1998. The transfer of the coupon was reported Wednesday afternoon on the website of the National Settlement Depository.