The SNP being led by a married couple was ‘central’ to the Peter Murrell scandal, Alex Salmond’s former chief of staff has said.

Geoff Aberdein said Nicola Sturgeon running the country while Murrell ran the party led to flawed governance, with genuine questions perceived as hostile and shut down.

It led to people who tried to scrutinise the party’s finances ‘ostracised or put on the sidelines’ five years ago, when concerns were first raised about missing money.

He said even Mr Salmond was ‘chewed out’ by Ms Sturgeon when he told her Murrell should not remain party chief executive after she became leader in 2014.

Speaking on the Holyrood Sources podcast about the marriage, Mr Aberdein, Mr Salmond’s top spindoctor from 2011 to 2014, said: ‘I wonder if this is central to the whole thing.

‘In no other walk of life would the chairman of an organisation and the chief executive of an organisation be married or in the same household.

‘It wouldn’t be acceptable in a charity, it wouldn’t be acceptable in a small or medium enterprise, it wouldn’t be acceptable in a big corporate.

‘I think the regulators would put paid to that, frankly.’

He said it had consequences for the operation of the SNP’s governing body, the National Executive Committee (NEC).

‘Within that you’ve got the party leader, who is on the NEC as a voting member,’ he said.

‘It’s made up of MPs, MSPs, some councillors. They’re responsible for political strategy, party governance, financial oversight, executive oversight.

‘And then attending that same NEC, but not with a vote, is Peter Murrell, who is accountable to that ruling body.

‘All of this was taking place in a very closed environment.

‘More strength to the elbow of the people that made their concerns known throughout this long saga. They found themselves pretty much ostracised or put on the sidelines.

‘Where was the scrutiny of all of this? Why was it not taking place?

‘I can only assume that having both the chief executive and the party leader and first minister within the same household and married cannot be helpful to that process. It just can’t, logically.’

Mr Aberdein, now a managing partner at public affairs consultancy True North Advisors, said he was ‘disappointed’ that John Swinney tried to ‘sidestep’ the issue when he gave a press conference on Monday after Murrell was remanded in custody following his guilty plea to embezzlement.

Peter Smith of ITV News had asked the First Minister if it had been ‘a mistake for the SNP to have allowed the chief executive to be married to the leader of the party’.

He replied: ‘Ultimately, the issues that are at stake here were all about the behaviour of Peter Murrell. Individuals are responsible for their own conduct and their own actions.’

Pressed on whether the governance had been inappropriate, the SNP leader said: ‘That’s not something that was within my gift. We now have good and strong governance in place.’

Mr Aberdein said Ms Sturgeon had ended up ‘writing herself into the story’ more than necessary by repeatedly issuing statements in person or via a lawyer insisting she was unaware of Murrell’s wrongdoing.

He said: ‘She obviously felt, or her legal representative felt, that it was important to get a clarification statement out there, and then another one.

‘But by doing so, you’re fanning the flames, you’re fuelling the story.

‘It was inevitable she was going to be the focus of a lot of attention, but clearly, when you’re trying to minimise the exposure, you want to get a one-and-done and get it out there, and then no more. But that’s not been the case.’