The Scottish Government has banned staff from using WhatsApp on their work phones after Nicola Sturgeon and John Swinney deleted all their pandemic-era messages from the platform.

Kate Forbes, the Deputy First Minister, announced mobile messaging apps would no longer be permitted on official Scottish government phones and tablets from next spring.

She said the SNP government had "reflected" on the policy it operated during the pandemic, which allowed ministers to destroy messages after any points they considered "salient" were added to the official record.

Her announcement was made alongside the publication of a review of the policy, which found that it was "clearly open to interpretation" about what information should be retained

The outcry by bereaved relatives over the mass deletion of messages prompted Humza Yousaf, who was then first minister, to order the review in March this year. Mr Swinney succeeded him in May.

But Ms Sturgeon, the first minister during the pandemic, had already started deleting her WhatsApps, despite promising during an August 2021 press conference that they would all be handed over to the UK public inquiry.

She and Mr Swinney, who was her deputy, continued deleting them even though the UK Government wrote to all devolved governments three times in 2022 asking for material of potential relevance to be kept and not destroyed.

The UK inquiry also wrote to the Scottish Government in August 2022 ordering ministers and officials to retain "all material that could be relevant", including "emails, text or WhatsApp messages and other communications".

It also emerged that Prof Jason Leitch, who was then Scotland's national clinical director, told colleagues in May 2021 that "WhatsApp deletion is a pre-bed ritual" - less than 24 hours after the UK inquiry was unveiled.

Unveiling the findings, Ms Forbes said: "We have carefully considered the recommendations and we will end the use of mobile messaging applications to conduct government business by spring 2025. At that point, mobile messaging apps will be removed from corporate devices."

She added: "The use of mobile messaging apps increased during the pandemic as staff worked remotely in unprecedented and difficult circumstances. Having reflected on our working practices, we are now implementing changes to the use of mobile messaging apps."

Updated guidance and training for staff and Ministers will take place ahead of the new policy being implemented.

But Dr Sandesh Gulhane, the Scottish Tories' Shadow Health Secretary, said: "The SNP must think Scots are buttoned up the back.

"It is astonishing that Kate Forbes says her party value openness and transparency after the nationalists spent the pandemic deleting WhatsApp messages on an industrial scale."

The review was conducted by Emma Martins, a former Channel Islands data protection commissioner, and handed to SNP ministers last month.

It found there was "little to evidence a consistent and widespread knowledge, understanding, or application" of mobile messaging apps, "including rules around retention, exportation, and deletion".

The review said that the Scottish Government's policy required ministers and officials to transcribe "salient" points from mobile messages to its Electronic Records and Document Management system.

But Ms Martins said: "In the absence of any information about how much or how often such transcribing took place, it is impossible to take any comfort from the policy."

She said the process was "unwieldy" and increased the likelihood of ministers or officials neglecting to "to take [the] required steps".

Giving evidence to the UK Covid Inquiry in January, Ms Sturgeon said she had not used informal platforms such as WhatsApp to "do government business related to Covid".

But the inquiry was shown a lengthy WhatsApp exchange obtained from the phone of Liz Lloyd, Ms Sturgeon's former chief of staff, in which she held detailed discussions with the former first minister about the opening hours of hospitality venues.

WhatsApp is banned in Iran and North Korea and earlier this year China prevented iPhone users from downloading it.

In April the UK Cabinet Office issued guidelines stating it must not be used for sharing anything above the lowest level of security classification.