Mitsubishi UFJ Financial Group has suspended two London-based traders amid a growing investigation into the suspected manipulation of the Libor interbank lending rate.
BTMU, a core commercial banking unit of Mitsubishi UFJ, Japan's largest lender, said the suspension was not related to work done for the Japanese bank.
Both of the traders worked at Dutch lender Rabobank before joining Bank of Tokyo-Mitsubishi UFJ, said a source, who was not authorised to discuss the matter publicly.
"BTMU is fully cooperating with authorities' Libor investigation. The stay-home instruction on the two has nothing to do with their work at BTMU," a bank spokesman in Tokyo said. He declined to comment further.
Bloomberg named the men as derivatives traders Christian Schluep and Paul Robson, citing a person briefed on the matter.
A Rabobank spokeswoman declined to comment on the traders.
Investigators in the United States, Europe and Japan are examining more than a dozen big banks over suspected rigging of the London Interbank Offered Rate (Libor).
Britain's Barclays has been the only bank to admit wrongdoing, agreeing last week to pay a fine of more than $450 million.
The Libor rates, compiled from estimates by large banks of how much they believe they have to pay to borrow from each other, are used to determine interest rates on trillions of dollars worth of contracts around the world.