This article appears as part of the Unspun: Scottish Politics newsletter.

The Lord Advocate didn’t stop to talk to journalists when she left the Holyrood chamber on Thursday.

She ignored the one question the waiting hacks shouted at her as she walked by: why on earth is Operation Branchform taking so long?

We know that Peter Murrell, the party’s former chief executive, was charged in April with embezzlement, but we still don’t know if prosecutors are going to, well, prosecute.

We know that Police Scotland handed a report to the COPFS two months ago asking for “advice and guidance” on what to do about Nicola Sturgeon and former treasurer, Colin Beattie, both of whom were arrested, questioned and released in April last year.

But the force says they are still waiting for “direction on what further action should be taken.”

Earlier this week, reports suggested police officers investigating what happened to £660,000 of donations given to the SNP by independence activists, had become "frustrated" with the Crown Office.

It has been over three years since the first complaints. It has over a year since the house of Peter Murrell and Nicola Sturgeon was raided, and a luxury campervan was seized by police. 

It is clearly a complex investigation. Of course, it is, but the voices calling for an update are getting louder.

Over the weekend, Sottish criminal defence lawyer Thomas Leonard Ross KC told Sky News the probe “cannot go on indefinitely”.

He said: “Once somebody is charged then they have the right to a trial within a reasonable time.

“Before a person is formally charged, there might be an argument as to whether the clock is efficiently running.

“There is absolutely no doubt that it is running in relation to Mr Murrell, so certainly the police and Crown Office have to be alive to that.

“The police inquiry cannot go on indefinitely.”

Get Scotland's top politics newsletter straight to your inbox.

 

It is also, a costly investigation. Figures obtained by LBC earlier this week, show that Police Scotland has now spent at least £1.8m on the investigation. 

Some £426,466 of that was between February and August this year. Around £95,391 is the overtime bill.  There is much we still do not know.

Last year the former chief constable, Sir Iain Livingstone, said the inquiry had “moved beyond what some of the initial reports were”. That was, he added, “not uncommon in investigations such as this.”

It is both unfair and entirely reasonable for the Holyrood press pack to doorstep Dorothy Bain KC.  As the public prosecutor, she is responsible for the COPFS.

But as the government’s legal adviser, she has had to excuse herself from acting as prosecutor in this case on the grounds that it is so highly political. 

That means the decision on whether to bring charges is in the hands of more junior advocate deputes.  Many legal types, including former SNP MP Joanna Cherry, have long suggested the Lord Advocate’s role be split to help avoid the “suspicion of political interference”.

That may end up being one of the legacies of Branchform. charges or not. At least then, we’ll know who to shout at.