The quality, integrity and sustainability of certain financial benchmarks, such as LIBOR, remains uncertain in the wake of the widespread market manipulation scandal involving major benchmarks, suggests a report published Tuesday from the Financial Stability Board (FSB).

The global policy group published a progress report on the implementation of recommended reforms to major interest rate benchmarks, which followed from the discovery of widespread manipulation of the rates by some of the world’s major banks. In response to that scandal, the FSB called for a variety of reforms designed to strengthen the calculation and governance of benchmarks based on interbank markets.

Although benchmark administrators have taken steps to implement the FSB’s recommendations, in some cases, they haven’t been able to move away from basing benchmarks on bank submissions that have proved vulnerable to manipulation, the report notes.

“Underlying reference transactions in some currency-tenor combinations are scarce and submissions therefore necessarily remain based on a mixture of factors including transactions and judgment by submitters,” the report says.

Additionally, although regulators have tried to address these issues through various means, the report cautions that, “it remains challenging to ensure the integrity and robustness of benchmarks and it is uncertain whether submitting banks will continue to make submissions over the medium to long-term.”

Finally, the report notes that regulators have also made “limited progress” at migrating to alternative risk-free rates; and, that with “questions surrounding the long-run viability of some IBORs, such as LIBOR … it is important that momentum is maintained to fulfil the FSB’s [risk-free rate] recommendations.”