The recent court case in Wellington where evidence was withheld from the defendant and their lawyer in the name of national security is highly concerning.

The case concerns a New Zealander living in Melbourne who had her passport cancelled by the then Internal Affairs Minister Peter Dunne. She appealed the decision but neither she nor her lawyer have been able to see the evidence used to justify the decision. The court did appoint an advocate on her behalf for that part of the trial, but what they did and where their loyalties lay is unclear.

We strongly oppose the use of secret evidence in court – as did Justice Dobson, the judge in the original trial:

The whole of our common law tradition, as bolstered by the rights and protections recognised by New Zealand Bill of Rights Act 1990, render the procedure under [the Passports Act] an anathema to the fundamental concepts of fairness.

The right to a fair trial is a key part of our justice system and this must include the right to see and test the evidence against you. It's impossible to rebut evidence when you don't even know what it says. It's hard to even appeal when the judgement against you omits critical details that the decision relied upon.

Appointing an advocate and letting the judge see the information is all very well, but as far as the defendant is concerned it's just one part of the state telling her that she can trust other parts of the state. This is no comfort when it's the state acting against you in the first place.

One could argue that without this evidence there would have been no grounds for cancelling her passport and obviously this is vital to our national security interests. Unfortunately the secrecy means we have no way of determining whether this is true. The credulous and sycophantic behaviour of our security services in the Kim Dotcom and Ahmed Zaoui cases do not inspire confidence.

Furthermore, we already accept that the courts have the power to exclude evidence that has been obtained unfairly or illegally, even when that evidence might be persuasive in making a decision. This is because the larger cause of justice is seen to outweigh the circumstances of a particular case. Secret evidence should be treated in the same way, unable to be used in court so as to protect the integrity of our justice system.

Civil liberties is always about making trade-offs but giving up important civil liberties should only ever be for equally important reasons. When it comes to the details of this case, it's hard to see how cancelling someone's passport so that they can't leave a foreign country could clear this bar. Could the possible damage caused by not making the decision ever exceed the damage this trial does to our civil liberties? We're told the secrecy is for "security reasons" but secret trials with secret evidence are a much more significant threat to our security and liberty.

We need to stop accepting the use of secret evidence in our courts, it has no place in a free and democratic society.

Further comment from:

• Andrew Geddis at the Spinoff – The bizarre case of the NZ court case hidden from public and media scrutiny
• Reported by Matt Nippert at the NZ Herald – Secret Wellington High Court national security hearing lambasted as 'Kafkaesque'
• Chief High Court Judge Geoffrey Vennin's explanation – Judge explains secret Wellington court hearing