Today's resignation of Ireland's police chief, Martin Callinan, is a vindication of the reporting of Gemma O'Doherty, a journalist fired by the Irish Independent for her pursuit of the story that has led to his departure.

As I reported in September last year, O'Doherty was made compulsorily redundant by the paper after door-stepping Callinan, the Garda commissioner.

She was following up a tip that penalty points had been wiped from Callinan's driving record. It came against the background of allegations by police whistleblowers that hundreds of people had also had penalty points removed from their licences.

But Stephen Rae, editor-in-chief of the Dublin-based Independent titles (and a former editor of the Garda Review magazine), was furious with O'Doherty. He called her a "rogue reporter" for approaching Callinan without permission.

Although her story was eventually run in "sanitised" form, she was informed that she was to be made redundant. She had been with the paper for 18 years and was regarded as one of its finest investigative journalists.

Last month, O'Doherty launched a defamation action against Rae and the Irish Independent, which is owned by Independent News & Media, seeking aggravated and exemplary damages.

Her lawyer, Paul Tweed, said it was the first of three legal actions. She will also take her case to Ireland's employment appeals tribunal and the personal injuries assessment board.

Tweed said O'Doherty was "devastated" by the way she has been treated by the Irish Independent after "doing her job to the same high standards that in the past had earned her unequivocal praise".

In September last year, the London-based Irish Post revealed that a car registered to Rae had had penalty points wiped in 2009.

In fact, the Irish Post is one of the very few newspapers to have reported the details of O'Doherty's firing. Ireland's domestic mainstream newspapers and its major broadcaster, RTÉ, ignored the story.

Callinan told a Dublin parliamentary committee that the claims about penalty points deductions by the whistleblowers - Sergeant Maurice McCabe and the now-retired John Wilson - were "disgusting".

But a report by the independent Garda Inspectorate considered McCabe's information to be "credible" and found that there were consistent and widespread breaches of policy by those charged with administering the penalty points system.

Comment: A journalist was interrupted in her duty to inform the public about a scandal involving a state's police force. Isn't that the whole point of our journalistic mission? Should she have been fired for that?

In the light of today's developments and the report by the independent Garda Inspectorate, it is surely time for Stephen Rae to consider his position and for Independent News & Media to consider reinstating O'Doherty. At the very least, Rae's links with Callinan and the Gardai require internal and external investigation.

Sources: BBC/Irish Post/Sunday Times/Irish Independent