THE SNP’s financial problems have spread to its £1.5million-a-year Westminster group with the departure of the same auditors who walked away from the party's headquarters.

The MPs’ group has yet to appoint new auditors despite a looming legal deadline.

It emerged this week that Johnston Carmichael had quit as the SNP’s financial overseers last September amid a police investigation, a fact that was hidden from the public until last week.

Humza Yousaf said even he didn’t know about the resignation until he was briefed upon becoming SNP leader in late March.

The development was only made public on April 7.

It is understood the SNP's ruling body, the National Executive Committee, was also kept in the dark.

READ MORE: SNP hid resignation of auditors for six months, Humza Yousaf reveals

Johnston Carmichael had signed off the SNP’s accounts for more than a decade, including the latest set for 2021 showing income of £4.5m.

The firm quit citing "a review of our client portfolio and existing resources and commitments".

The First Minister said on Tuesday that the chartered accountants had resigned “around” last October, but it is understood they actually gave notice in September.

The Herald can now reveal that Johnston Carmichael also stopped acting as auditors for the SNP’s Westminster Group around the same time.

Again, the SNP did not publicise the exit.

At the time, the treasurer of the SNP Westminster group was Glenrothes MP Peter Grant and the “second officer” was then group leader Ian Blackford. 

New Westminster leader Stephen Flynn now faces questions about what he knew about a lack of auditors when he replaced Mr Blackford in December.

The SNP Westminster Group is the party’s second largest “accounting unit”, and helps run research and staffing budgets for its 45 MPs at the Commons.

It regularly has an income of more than £1m a year, most of it from so-called “short money”, which is given to opposition parties by the Parliament, and so requires its own audit.

Like the central party, it has a legal duty to file its accounts for 2022 with the Electoral Commission by July 7 or it could be fined.

Mr Yousaf has admitted that hitting the deadline will be “challenging”.

The departure of the auditors came amid a long-running police investigation into the SNP’s finances after claims of potential fraud.

Police Scotland launched Operation Branchform in July 2021 after complaints that £660,000 raised specifically for a second referendum campaign may have been spent on other things.

Last week officers arrested and questioned former chief executive Peter Murrell, the husband of Nicola Sturgeon, before releasing him without charge.

The police also searched the couple’s Glasgow home and seized a luxury £110,000 motorhome from outside the house of Mr Murrell’s widowed 92-year-old mother in Fife.

READ MORE: Humza Yousaf rules out SNP paying Peter Murrell's legal fees

The SNP said Johnsoon Carmichael informed the party in September that they would not be able to conduct the audit due in 2023 “following a review of their client portfolio”. 

The firm raised no concerns about the audit of the SNP’s 2021 accounts, which it had conducted and which gave the bookkeeping a clean bill of health.

The SNP said it had approached other firms in late 2022, but found a number of firms were “experiencing capacity issues… and unable to take on new clients”.

The search intensified in the New year with a number of firms contacted, but as yet, no auditor “with the required capacity has been identified”.

Labour and the Tories have demanded greater transparency from the SNP, saying the failure to be open about its auditors “stinks to high heaven”.