I had the privilege, until quite recently, of chairing the New Zealand national commission for Unesco.
During my term as chairman, my fellow commissioner, Paul Smith, established - with my support - what we called the Freedom Page on the commission's website.
Our goal was to raise awareness of the importance of press freedom and of the threats to that freedom - particularly, and sadly, in some of our Pacific neighbours. There was, however, some nervousness when we made it clear that the Freedom Page would not shrink from drawing attention to similar issues if and when they arose here.
New Zealand enjoys, of course, an enviable record, in international terms, in matters of freedom of expression. It would be ridiculous to claim that a New Zealand government might pose a direct threat - through censorship or the abuse of executive power - to our press and broadcast media and their freedom to publish what they wish.
But threats to press freedom can come in much more insidious forms - and two recent instances make the point clearly.
Many will recall the extraordinary episode of the Prime Minister's conversation over a cup of tea with John Banks during the election campaign. The Prime Minister was clearly very keen that the contents of that conversation should not be made public.
When it became clear that a record of that conversation was in the hands of the media, and that they saw no legal problem in publishing it, the Prime Minister's reaction was very instructive.
He did not go to court to seek an injunction and assert his right to privacy. Instead, he laid a complaint with the police and asked them to investigate what he maintained might be a criminal offence.
The police were quick to comply.
They not only initiated an investigation but also warned the media that they, too, could be criminally liable if they published the recording. This warning was sufficient to frighten the media into silence.
Two months later, we are still waiting for the outcome of the police investigation. No criminal offence, it seems, has yet been established. The only legal outcome so far is that the Attorney-General, acting for the Government, has declared his intention to seek substantial costs from the cameraman who had the temerity to try to establish if he had committed no offence.
The police investigation, while so far inconclusive on the issue of criminality, has nevertheless been successful in another respect; it has fully met the Prime Minister's requirements by keeping the conversation secret till beyond - well beyond - the election.
The message is clear. The police will support threats issued by the executive to deter the media from publishing material that as far as we know was lawfully obtained and that was of substantial public interest.
And just to make sure, the Attorney-General's threat to the cameraman is a warning to others that they cross the executive at their peril.
Some of the same features are shown by the issue that became public last week. New Zealand On Air has expressed concern that a programme on child poverty it had funded was broadcast in the days leading up to the election.
It has announced that it may seek legal advice on obtaining a law change that would give it the power to delay until after an election a broadcast that might embarrass politicians.
What is worrying about this episode is that an expression of concern from the Prime Minister (in this case, through his electorate chairman who is a board member of NZ On Air) about a perfectly lawful broadcast was enough to induce the body that has a public duty to fund such programmes to seek to limit the freedom of the broadcasters.
Again, it is not any direct threat or interference that is of concern; rather, it is the threat that the executive is ready to act against anything that displeases the Prime Minister.
Who can doubt that broadcasters will in future make sure their programmes do not attract prime ministerial displeasure and risk losing the necessary funding? And others in the media will also learn the lesson - if they want to get on, they must stay on the right side of the Prime Minister.
To make these points is not to attack the Prime Minister. He is doing what many politicians in government around the world would do if they could get away with it. It is, rather, a clarion call to journalists and to the public to stand up for press freedom and the independence of the media.
The threat is always there, and it is particularly acute in the case of this Prime Minister - not because he is especially unprincipled or autocratic, but because his very popularity might encourage him to think he can get away with more than he should.
We are entering dangerous territory if the flow of information and opinion can be turned off or diverted by the mere expression of prime ministerial concern.
It was Thomas Jefferson who warned that "the price of freedom is eternal vigilance". That vigilance must be alert to the subtle nature of today's threats to press freedom.
Bryan Gould is New Zealander who was a British Labour MP and vice-chancellor of the University of Waikato.