Instant messages show trader Tan Chi Min telling colleagues the bank’s submissions changed the rate and so global interest rates.
A message from April 2008 read: “Nice Libor. Our six-month fixing moved the entire fixing, hahahah.”
Libor is a key interbank lending rate which banks use as a benchmark and to judge the state of funding markets. Banks give estimates of interest rates to the British Bankers’ Association, which compiles the number daily.
The messages emerged because Tan was sacked last year for allegedly fiddling the Libor submission, and is suing RBS for wrongful dismissal.
The documents were seen by Bloomberg before Singapore’s high court sealed them as the papers could prejudice other inquiries.
Tan denies any wrongdoing, arguing the bank approved the practice at the time.
Other messages show conversations between then-head of yen products Jezri Mohideen, who denies wrongdoing, and Neil Danziger who has since been fired.
Mohideen is reported to have asked “What’s the call on Libor,” to which Danziger replied “Where would you like it, Libor that is.”
Another trader said: “Mixed feelings, but mostly I’d like it all lower so the world starts to make a little sense.”
An RBS spokesman said: “Our investigations into submissions, communications and procedures relating to the setting of Libor and other interest rates are ongoing. RBS and its employees continue to cooperate fully with regulators.”