Not for the first time, this column is indebted to Tory MSP Mary Scanlon, that tireless scourge of government backsliding (in Scotland at least).

She is keeping us abreast of progress on the replacement for HM Prison Inverness, or Porterfield as it is commonly known (having been originally called after the local parish of that name where it was built) .

In fact, Ms Scanlon has discovered there has been a distinct lack of progress on this front. Five years after it was first announced, there is still not even a site for the new jail.

As depute convener of the Scottish Parliament's Public Audit Committee, she had asked for an update from Alyson Stafford, Director-General of Finance in the Scottish Government.

Ms Scanlon said the committee had been looking for an explanation of the time taken to prepare the project and the increase in costs since it was first announced in 2009.

She said it had been clear for many years that the current prison, which opened in 1902, was struggling to meet the needs of the modern prison service and had been subject to several critical reports by HM Inspectors, not least on overcrowding.

Ms Scanlon said: "There was widespread support for a new prison when the SNP Government announced their plans back in 2009 but five years later it seems we are no further on. It is disappointing that there is still no site for the prison which is now scheduled for 2018.

"The original cost in 2009 of HMP Highland was £40m and is now estimated at almost £63m yet the Scottish Prison Service state there has been no reported increase in the cost of the project since it was announced in 2009."

A Scottish Prison Service spokeswoman responded: "We have funds set aside in our budget 2014-15 to purchase a site for HMP Highland. Despite identifying a number of sites we have been unable to secure one as yet. We will continue to work with Highland Council to identify a suitable site. "

So, in the meantime, around 150 wrongdoers will continue in their cells surrounded by some of the most desirable property "on the hill" of the Highland capital. Indeed flogging off the prison site will eventually earn the Scottish Government a nice little return, although perhaps not quite £63m.

However, Ms Scanlon's bulletin has got The Highland Line wondering whatever happened to the bold idea that her fellow MSP Dave Thompson came up with for HM Prison Inverness - build the replacement in or around Dingwall.

The SNP MSP for Skye, Lochaber and Badenoch mooted his alternative plan a year and a half ago, but little has been heard of it since.

He has a constituency office in Dingwall, which will lose its sheriff court next month (Jan 2015) when it closes under rationalisation plans. These will see services centralised in Inverness.

But Inverness Sheriff Court is located in Inverness Castle and there is growing demand for this imposing building sitting above the River Ness to realise its considerable potential as a tourist attraction. (It could possibly even feature its former function as the prison before Porterfield was built in what apparently were fairly rural settings at the start of the 20th century.)

At any rate, Mr Thompson suggested a state-of-the-art new justice centre in Dingwall should be considered. This would have a new court with the new prison next door, presumably with a fairly high wall in between.

Early indications were that the idea was being taken seriously by the authorities. But things have since gone quiet, which is a shame because the proposal has some merit.

There certainly is no reason why the new prison has to be in Inverness and the castle really should be embarking on a promising career as a tourist magnet. This could be a catalyst for the frequently proposed redesign of the Highland capital's centre along the riverside.

So why not send miscreants to Ross-shire's county town? It has a rail station, good road connections and bus services, and is less than 15 miles from Inverness.

Such a major capital project would be a massive boost to the local economy in and around the town and right along the Easter Ross Peninsula and the Black Isle. There would also be employment opportunities after completion.

Indeed, even Ross County FC could have a role to play in the rehabilitation process of inmates, with those nearing release allowed to attend matches.

Mind you, given the team's performance to date this season, such a move would be more likely to be deployed as a sanction or punishment for prisoners behaving badly....