None of ICAP's senior management were ever aware of, or involved in, the attempted manipulation of benchmark interest rates, the British broker said in a statement on Thursday.

Citing sources familiar with the matter, the Wall Street Journal said on Wednesday that ICAP executive David Casterton was included on emails sent in 2007 that documented discussions between ICAP brokers and officials at UBS.

In those emails, UBS had agreed to make quarterly payments to ICAP for help in rigging Libor (London Interbank Offered Rate), the Wall Street Journal said.

"Neither the company nor its senior management was aware of any corrupt payment from any source at any time. All payments received from UBS were documented and invoiced," ICAP said in an emailed statement on Thursday.

"ICAP strongly refutes that Mr Casterton or anybody else in ICAP senior management were ever aware of, or involved in, any improper activities in relation to the attempted manipulation of yen or any other Libor. Any suggestion otherwise is false and defamatory."

David Casterton is currently head of global broking at ICAP. He could not immediately be reached for comment.

British and U.S. regulators have so far fined three banks a total of $2.6 billion over the Libor rigging scandal. Two men have been charged over the rigging.

Last week, British prosecutors alleged in court that former UBS and Citi trader Tom Hayes had conspired with employees from at least 10 financial institutions, including ICAP, to manipulate interest rates over four years.

In its settlement last year with British and U.S. regulators over the rate-rigging, UBS admitted that its traders paid bribes to brokers in return for their help in fixing rates. It did not identify the brokers.

These brokers accepted "corrupt payments" from UBS and also engaged in wash" trades - where a bank does two trades that effectively cancel each other out - to earn more than 170,000 pounds in commission, UK regulators said in the Dec. settlement.

ICAP chief executive Michael Spencer has since said that the brokerage, after conducting internal investigations into possible rigging, had found no signs of telltale "wash trades" used by banks to reward brokers.

Terry Smith, the CEO of rival Tullett Prebon, said in March that the firm's internal probes had found wash trades, including interest rate products, but that these were a common way for brokers and clients to remunerate each other and that there was no evidence they were linked to Libor manipulation.