The most senior Catholic leader in England and Wales went to extraordinary lengths to try to discredit a BBC documentary on child sexual abuse and its cover-up by the church, the Guardian can disclose.

Cardinal Vincent Nichols, the archbishop of Westminster, publicly accused the BBC of bias and malice before the documentary was aired in 2003. Documents seen by the Guardian show he also lobbied the BBC’s director of news, wrote to all priests in his archdiocese urging them not to speak to BBC journalists, and lodged a formal complaint against the programme’s makers.

The BBC’s programme complaints unit (PCU) rejected the complaint, and the BBC governors’ programme complaints committee dismissed his appeal against that decision. Nichols refused to apologise to the programme-makers.

Last month the independent inquiry into child sexual abuse (IICSA) criticised Nichols for putting the church’s reputation before the welfare of abuse survivors. In a report, IICSA said Nichols’s response to the BBC programme was “misplaced and missed the point”.

The documentary, part of the investigative series Kenyon Confronts on BBC One, included interviews with survivors who claimed the church covered up cases of sexual abuse. It tracked down Father James Robinson, a Catholic priest who fled to the US after being accused of sexual abuse and who received financial support from the Catholic archdiocese of Birmingham for seven years before he was extradited, convicted and jailed.

At the time of the documentary, Nichols was archbishop of Birmingham and chair of the Catholic Office for the Protection of Children and Vulnerable Adults.

At a press conference before the programme was broadcast, Nichols accused the BBC of “using the licence fee to pay unscrupulous reporters trying to recirculate old news and to broadcast programmes that are biased and hostile”.

He added: “That this programme has been allowed to progress this far shows either malice towards the church or a total lack of judgment or of managerial responsibility.” He demanded the BBC justify the renewal of the licence fee.

While the documentary was being made, Nichols wrote to priests in his archdiocese urging them not to speak to BBC reporters working on it. “If you are approached please remember you are not advised to be cooperative. You may, quite properly, refuse to take part in any questioning or interview. This is my advice,” he wrote.

Before broadcast, Nichols wrote to Richard Sambrook, then the BBC’s director of news, saying a re-examination of historic sexual abuse cases was not in the public interest. He claimed reporters had telephoned a priest at 2am, acted discourteously and inconsiderately to a priest who had just undergone major surgery, and “cornered” a priest in a residential care home to question him.

Sambrook told the Guardian: “My recollection of the difficult meeting and correspondence with Cardinal Nichols is that he was entirely focused on trying to discredit the BBC’s journalism in the hope of diverting criticism of the church. Fortunately the BBC’s journalism was sufficiently robust to see off such attempts. He showed little interest in wider questions about uncovering abuse or the welfare of the survivors.”

After the programme was broadcast on 15 October 2003, Nichols lodged a formal complaint with the PCU, claiming BBC reporters used underhand methods to gain access to elderly and infirm priests.

The PCU rejected Nichols’ complaint, saying there were no grounds for his claim that the Kenyon Confronts team behaved inappropriately. It said the investigation was “conducted properly and in line with BBC producers’ guidelines” and there was no evidence of serious breaches of editorial standards.

Some of the 11 sworn witness statements from nuns and priests provided by Nichols to the PCU contradicted his allegations that reporters had not properly identified themselves. Evidence from recordings of some encounters also showed his claims to be false.

Nichols claimed one priest had been left distressed by a visit from two members of the Kenyon Confronts team, who were alleged to be hectoring and intimidating. However, the priest’s statement said the pair were “well-mannered, polite and had respect for my office, although I was glad when I had finished speaking to them. They were not unpleasant or malicious in the way they spoke to me.”

Nichols appealed to the BBC governors’ programme complaints committee against the PCU’s adjudication, and in May 2005 the committee rejected the appeal.

After the decision, Paul Kenyon, the programme’s presenter, and Paul Woolwich, its executive producer, wrote to Nichols saying the archbishop had tarnished the reputation of those who worked on the documentary. “We believe an apology to set the record straight would now be appropriate.”

Nichols replied: “I see no need for me to offer an apology.”

Last month IICSA said Nichols’ response to the programme should have focused on “recognising the harm caused to the complainants and victims. Instead, [it] led many to think that the church was still more concerned with protecting itself than the protection of children.”

After the report was published, the Tablet, a respected Catholic weekly, said the inquiry’s criticisms raised questions about Nichols’s fitness for office.

In a statement to the Guardian, Nichols apologised for at the time failing to sufficiently acknowledge two positive elements of the programme: giving a platform to abuse survivors and locating Fr Robinson.

He pointed out he had offered to give a live interview to the BBC at the time of the broadcast. Woolwich said it had not been possible to broadcast a live interview immediately after the broadcast of a pre-recorded programme, and Nichols had rejected an offer to appear live on Newsnight the same night or the Today programme the following morning.

Nichols’s statement said: “I was annoyed at the approach of the programme-makers who gave a slanted presentation of the real problems we were seeking to address … I accept that my frustration at the approach of the programme-makers led me not to give sufficient attention to the suffering of the victims of abuse perpetrated by the priest in question, although I had already met with all but one of them.

“A more thorough listening to the experiences of victims and survivors has now become central to the church’s approach and we will continue to adjust our work in safeguarding in light of this victim-centred approach.”