An HSBC manager didn’t adequately probe claims of gross misconduct, a tribunal was told today.

Lawyers for Peter Lewis, who claims he was sacked from the bank because he was gay, accused Mark Bucknall, HSBC’s co-head of global investment banking, of being biased after not considering Mr Lewis’s side of the story before dismissing him.

43-year-old Mr Lewis, was dismissed by the banking giant for “gross personal misconduct.” The incident in question relates to an encounter between Mr Lewis and another male employee of the bank, which ultimately resulted in a complaint of “sexual harassment.”

Chris Quinn, Mr Lewis’s lawyer, cross examined Mr Bucknall and suggested he didn’t adequately investigate eight discrepancies in the complainant’s story or if he was homophobic, given his use of words such as “effeminate” and “nonce,” a slang term for a paedophile, when referring to homosexuals.

He said: “You don’t appear to have given Mr. Lewis the benefit of the doubt on a single issue.”

Mr Bucknall denied that the former banker’s sexuality came into his decision.

He told the tribunal that he believed the employee who brought the complaint, who can’t be named for legal reasons, gave a more “credible” version of events and that Mr Lewis’s assertion that HSBC discriminated against his sexual orientation from the start were “ridiculous,” given the damage his dismissal has caused to the lender’s bid to rebuild its equities business.

Mr Lewis is seeking £5 million compensation at the hearing which is expected to end this week.