Kate Forbes has piled pressure on Nicola Sturgeon after revealing that she has retained all of her pandemic WhatsApp messages.

Speaking to journalists in Holyrood, the former finance secretary said she had not deleted anything.

That is despite Humza Yousaf claiming on Monday that the Scottish Government's social media policy at the time was to “routinely delete WhatsApp messages.”

READ MORE: Nicola Sturgeon says 'I have nothing to hide' but silent on WhatsApps

Asked if she had kept her messages, Ms Forbes replied: “I have. I have not deleted anything, I've retained all relevant correspondence. And that includes retaining all my WhatsApp messages.”

Asked if she was surprised to hear Mr Yousaf say the government’s policy was to delete messages, the MSP said: “Well, I suppose my approach has been that where something is relevant to my role as minister, I have retained it.

“And if I could take a step back, and just quickly say that it's really critical that the Covid inquiries provide answers to all those that were affected during the Covid years. And I think that calls for the greatest possible source of information, correspondence and evidence, and so on.”

On Tuesday night Ms Sturgeon insisted she had “nothing to hide” but repeatedly refused to say whether she deleted WhatsApp messages related to the Covid pandemic.

That followed the Sunday Mail reporting at the weekend that key Covid-related messages sent by the former first minister had been wiped from her phone.

Ms Sturgeon said her submission to the UK Covid inquiry - which is confidential until the probe chooses to make it public - would explain, “how I worked during the Covid pandemic, what I hold, what I don’t hold, and the reasons for that.”

Other reports have suggested both National Clinical Director Professor Jason Leitch and Chief Medical Officer Professor Sir Gregor Smith may have deleted messages either manually or through the use of the app’s auto-delete function.

READ MORE: OPINION: Nicola Sturgeon has questions to answer over Whats App messages

Last week, Jamie Dawson KC, counsel to the UK inquiry, said 70 Scottish government figures were asked for their WhatsApp messages, but "very few appear to have been retained".

He said this was "surprising" and that the "process of recovery had gone more slowly than expected".

The lawyer also revealed that there were at least 137 WhatsApp groups being used across the Scottish government and its agencies during Covid.

Ms Forbes said that to the best of her knowledge, she was not a member of any of the groups.

Asked how often she used WhatsApp, she replied: “Very rarely. It's not something that I've used very often, I certainly didn't make any decisions about Covid via WhatsApp. And if you recall, I was fairly new in the door when Covid started. So still very much finding my feet.”

She said the initial statement she had provided for the Inquiry “was extremely long” and was indicative of her “willingness to continue to cooperate.”

Asked why she was being more open with journalists, than Ms Sturgeon, the ex-minister said: “Well, I'm here on my own behalf, responding to questions that are being put. Obviously, the Covid Inquiry will run, has been running for a number of months.

“And all ministers and former ministers, like myself, will be obliged to give an account of our decisions that were made during the inquiry.”

Asked why she thought Ms Sturgeon had been so reluctant to answer questions about deleted WhatsApps, Ms Forbes replied: “I speak for myself. And I think it's incumbent on each of us to give an account for our own actions and our own decisions. It's incumbent on all of us, but I can only speak for myself. And that's why I'm here responding to your questions.”

Scottish Conservative leader Douglas Ross said the intervention raised more questions.

He said: “Kate Forbes’ confirmation that she retained all WhatsApp messages contrasts sharply with the evasion of Nicola Sturgeon when repeatedly asked the same question.

“It also further undermines Humza Yousaf’s claim on Monday that it was SNP Government policy to delete these messages. If this was true, why did the then health secretary – Humza Yousaf himself – and the then finance secretary openly breach cabinet policy?

“The First Minister must urgently clear up this contradiction, while Nicola Sturgeon must come clean and answer a simple question. She can’t continue to, contemptuously, hide behind process, when that hasn’t prevented Kate Forbes or Humza Yousaf from answering it.”