Brokers conspired with a currency trader to fix international bank lending rate in exchange for offers of treats like takeaway curries and drinks, a London court has been told.
The six brokers, including Wellington-based Briton Darrell Read, 50, are alleged to have helped Tom Hayes manipulate the Libor rate over four years.
Hayes, who was convicted of conspiracy to defraud earlier this year, repeatedly asked them via instant messages and emails for help getting Libor (London Interbank Offered Rate) set in his favour, Southwark Crown Court heard on Wednesday (UK time).
The jury was shown the messages and emails, and played recorded phone calls in which the prosecution claim the men explicitly discuss illegally helping him.
They included messages between some of the men and Hayes in 2006, when he was working for UBS in Tokyo, in which he offered to pay for curries if they helped him with multi-million pound yen currency trades by manipulating the Libor rate.
The six brokers - Read, 50, Noel Cryan, 49, Danny Wilkinson, 48, Colin Goodman, 53, James Gilmour, 50, and Terry Farr, 44 - are accused of conspiracy to defraud.
In one message in October 2006, Read, who worked for brokerage ICAP, told Hayes he could help him with a Libor rate, adding: "Got to buy the cash boys a curry this week."
Hayes replied: "I should pay it for them."
Read then said he would put it on his expenses.
In an email around the same time, during his first weeks working in Tokyo, the court heard Hayes wrote: "Should be good news today, Libor went up half a base point. Well done Darrell and Terry (Farr). I owe them a beer."
The court heard that Read, whose shift pattern was altered to allow him to work with Hayes while in a different time zone, would use ICAP colleague Goodman to manipulate Libor on Hayes's behalf.
In an October 2006 email exchange over setting Libor rates, Goodman told Read: "K10 (a restaurant) for lunch or cash would be preferable. Out for curry tonight."
Prosecutor Mukul Chawla QC told the jury: "It is small things like beers or a curry. The process is not so trivial."
Libor underpins hundreds of trillions of dollars of contracts, from mortgages to corporate lending.
The trial is set to last 12-14 weeks.