One of the consequences of the Freedom of Information Act has been that those public bodies captured by the legislation have become much more skilled in dodging requests.

They have also become much more - let’s say creative - in drawing up grounds for refusal notices, other than the standard reliance on Section 36 and Section 35 exemptions for when they can’t think of any other.

A case in point is one the KM Group lodged with the Home Office, requesting details of the costs associated with the Calais wall, which was built at the port as part of a UK deal to strengthen border security over the channel.

Although there had been reports of the estimated construction costs, we were interested to see if there were on-going costs associated with maintaining and repairing the wall; as well as the precise amount it had cost the UK taxpayer.

The Home Office responded with a refusal notice. The grounds for the refusal rested on four exemptions, namely: that disclosure would be prejudicial to international relations; health and safety; commercial confidentiality and the prevention and detection of crime and immigration control.

The response confirmed that the Home Office held the information we had sought but after “careful consideration” of the various public interest tests in each case, had decided none of it should be disclosed.

It laid out careful arguments which gave every impression that it had considered the information closely, such as this on the possibility of compromising crime detection:

"It is considered that disclosure of the information could assist those engaged in criminal activities at the UK’s borders as well as controls at Calais. Disclosure may enable potential offenders to circumvent the controls by building up a picture of our operational priorities, activities and areas of highest risk. This insight could be used by individuals with criminal intent to make an assumption on the effective use of Border Force strategies for tackling abuse of border controls, which would not be in the public interest."

Similar care appeared to be given to the arguments around international relations:

“The effective conduct of international relations depends upon the UK being able to reach agreements and maintain cooperation with other countries. The disclosure of information detailing the border arrangements at juxtaposed controls at the Calais ports, could potentially damage our inter country relationship. Hard fought agreements could be severely undermined and existing negotiations with the French government could cease.”

And on commercial confidentiality, the response said:

“There is a public interest in Government departments being able to secure contracts that represent value for money and anything that would undermine this is not in the public interest.”

As responses go, it did at least have the merit of applying the exemptions to the particular information being requested, unlike some of the cut-and-paste refusals the media frequently deal with.

We responded with an appeal, arguing that the exemptions engaged were inappropriately applied.

The appeal pointed out that it was hard to see how disclosure of financial costs would undermine law enforcement and pointing out that we had not requested any information around operational issues.

On commercial interests, we argued that the security wall was unique and it was unlikely that the government would be procuring any other similar schemes - thereby diminishing the weight of the argument against disclosure.

And we underlined our view that disclosure of the costs would allow people in the UK to make a judgement about whether the government was securing value for money.

Some weeks later, the Home Office responded, which is where it became interesting.

Although it had initially said that it held the information - and had considered it carefully - this was contradicted by the internal review letter:

"All security infrastructure and resource work has been instigated, procured, managed and delivered by the Port Operators. It is the Port Operator that holds the contract for delivery of this work. The UK Government involvement is that it provides the majority of funding via the UK – France joint fund to allow these projects to be progressed. Border Force then assures that funds are used appropriately and that value for money is delivered for UK taxpayers. As such the Home Office does not hold the requested information."

This inevitably raised the question of how, if the Home Office did not hold the information, did it carry out the “careful consideration” it claimed it had and how did it arrive at the conclusion that releasing it would not be in the public interest to do so?

The appeal also failed to persuade the Home Office that it should release details of the costs of building wall - information that it did hold.