Nigel Osborn-Clark, 37, who worked in Bristol, hanged himself last year.

In October 2003 an inquiry was launched after he was found to have opened his wife's file, breaking misuse rules.

The IR failed to ensure he was given an interpreter for an induction session on misuse policy, it was ruled. His family will now seek damages.

In reaching its judgement, the employment tribunal upheld a complaint brought by the family.

BBC Labour Affairs Correspondent Stephen Cape said: "The tribunal agreed that he had been deeply affected by the disciplinary proceedings, not realising that he had done anything wrong."

"Mr Osborn-Clarke's distress was connected with his deafness" - Employment tribunal

The Bristol-based tribunal accepted that Mr Osborn-Clark had made remarkable progress despite his disability.

In October 2003, when he was summoned to see a manager over the alleged incident of misuse, he admitted accessing his wife's file and became "extremely distressed", taking the next day off sick.

"Mr Osborn-Clarke's distress was connected with his deafness," the tribunal said.

"Because he was married with a young child and another on the way, the family were dependent on his earnings and his disability meant that the number of jobs available to him was limited."

'Serious view'

A dismissal for gross misconduct would make it "very difficult" to find another job, "more difficult than for a hearing person", it said.

A letter, sent to Mr Osborn-Clarke in December 2003, set out the charges he faced and stated that the IR took "a very serious view" of the situation.

Revenue employees facing allegations, the tribunal said, were left in a state of uncertainty for a period of months.

He hanged himself on 28 January 2004.

"It is impossible for us to speculate as to the reasons why Mr Osborn-Clarke killed himself," the tribunal said.

"It seems clear that he was deeply affected by the disciplinary proceedings brought against him and that he expressed himself to be concerned as to what would happen to him and his family if he lost his job."

'Deep sympathy'

The tribunal found that the IR had breached the 1995 Disability Discrimination Act by failing to provide Mr Osborn-Clarke with a sign language interpreter for an induction process on its computer misuse policy.

"Our policy on discrimination goes beyond our legal objectives" - Inland Revenue

The IR expressed deep sympathy to Mr Osborn-Clarke's family and said the department had a strong diversity and equality policy and always took discrimination allegations very seriously.

"Our policy on discrimination goes beyond our legal objectives," its statement said.

"We will of course look in detail at the tribunal's decision in this particular case."