Barclays had a "culture of gaming" and its problems came from "the tone at the top", a leading banking regulator has claimed.

Andrew Bailey, head of the Prudential Business Unit at the Financial Services Authority (FSA), described the bank's former chief executive Bob Diamond's account of his and Barclays relationship with regulators as "highly selective".

Mr Bailey told MPs on the House of Commons Treasury Select Committee yesterday there "was a problem with the institution and that came from the tone at the top", meaning Mr Diamond.

Former Barclays chief operating officer Jerry del Missier confirmed he had told the bank's money market desk to lower Libor submissions in October 2008 because he believed the Bank of England had directly instructed the bank to do so.

He also revealed Barclays' compliance department, which is responsible for ensuring policies and procedures are adhered to, was made aware of the request.

FSA executive chairman Lord Adair Turner said Mr Diamond was aware the regulator had sent a letter detailing issues with Barclays' culture, contradicting his evidence.