Former Barclays boss Bob Diamond was "highly selective" in his evidence to MPs, a powerful Parliamentary committee has concluded.
The Treasury Select Committee said Mr Diamond's evidence on the Libor fixing scandal had fallen well short of the standards expected by Parliament.
The MPs report follows in the wake of the Libor rate rigging scandal which saw Barclays fined almost £60 million in June.
In the report, the Bank of England was cleared of directing Barclays to artificially lower the Libor rate, as MPs found the bank was already doing so and it "did not need a nod, a wink or any signal from the Bank of England" to do so.
However both the Bank of England and the Financial Services Authority (FSA) were criticised in the report for failing to spot the manipulation of the Libor rate.
And the MPs found that "it is highly unlikely Barclays was the only bank attempting this".
Publishing the preliminary findings report, committee chairman Andrew Tyrie said: "The Committee has called for action in a number of areas, including: higher fines for firms that fail to cooperate with regulators, the need to examine gaps in the criminal law, and a much stronger governance framework at the Bank of England.
"The sustained rigging of a crucial benchmark rate has done great damage to the UK's reputation. Public trust in banks is at an all time low.
"Urgent improvements, both to the way banks are run and the way they are regulated, is needed if public and market confidence is to be restored.
"Select committees are entitled to expect candour and frankness from witnesses before them. Mr Diamond's evidence, at times highly selective, fell well short of the standard that Parliament expects, particularly from such an experienced and senior witness."
Mr Tyrie, a Tory MP, said he and his colleagues found the problems at Barclays went far beyond the fixing of Libor submissions.
He said: "Such misconduct is a sign of a culture on the trading floor, and higher up, that had gone badly awry."
A Barclays spokesman said they will "carefully consider" the report, adding they had established an independent review of their business practices.
The British Bankers' Association (BBA) said: "This is a significant contribution to the work the British Bankers' Association and the regulatory authorities have been undertaking to ensure the integrity of the benchmark.
"The BBA is providing the research and findings from its current review to the Wheatley review and is engaging constructively with the Parliamentary Commission on Banking."