The regulator didn't specifically suspect anything re: propensity for manipulating Libor, just a general feeling it couldn't necessarily trust the guy, which Barclays chairman Marcus Agius conceded was not entirely off base.
On Wednesday a British parliamentary committee release an internal record from the Financial Services Authority dating back to September 2010. The note details a discussion between Barclays Chairman Marcus Agius and then FSA chief Hector Sants during the final stages of the regulatory approval process for Mr. Diamond's promotion to CEO. In the note Mr. Sants said that Mr. Diamond had not reached "the level of openness, transparency and willingness to air issues with the FSA" of his predecessor. Mr. Agius agreed and said that the outgoing Barclays CEO John Varley would "coach" Mr. Diamond on the issue...During a meeting with lawmakers after Mr. Diamond's resignation, Mr. Agius said that the Libor issue had not been raised by the FSA when it vetted the CEO.