US politicians are considering calling on Bob Diamond, the former Barclays chief who stepped down after the LIBOR-fixing scandal broke out, to testify, according to media reports.

US politicians are considering calling on Bob Diamond, the former Barclays chief who stepped down after the LIBOR-fixing scandal broke out, to testify, according to media reports.

Both the Senate banking committee and the House financial services committee are considering the move, the Guardian reports, citing sources close to the matter. The committees are believed to have begun gathering information, and are expected to call Diamond after the summer recess.

Senator Tim Johnson, chairman of the Senate banking committee, said on Tuesday that his committee will hold hearings in July with Tim Geithner, treasury secretary, and Ben Bernanke, chairman of the Federal Reserve.

“It is important that we understand how any manipulation may impact American consumers and the US financial system…I am asking them [Geithner and Bernanke] to be prepared to answer Senators’ questions on this matter,” said Senator Johnson.

The senator said he was “concerned” about “growing allegations of potential widespread manipulation of LIBOR and similar interbank rates by some financial firms.” Committee staff have begun scheduling bipartisan briefings with relevant parties to “learn more” about these allegations.

The London Interbank Offered Rate for the US dollar is set based on information provided by 18 global financial institutions, including several US banks, and is used in interest rate derivatives contracts, as well as to set interest rates on a variety of financial products from mortgages to credit cards.