PETE Wishart has renewed the SNP's demand for answers over dark money donations to the Scottish Tories, saying the questions are "piling up at Ruth Davidson's door".

The Electoral Commission is examining the Scottish Unionist Association Trust (SUAT) over its links to the Scottish Tory party, having donated nearly £320,000 since 2001.

SNP MP Wishart called on Davidson to confirm whether SUAT donations went to the 2017 General Election campaigns of John Lamont, David Duguid and Douglas Ross, and whether election expense returns were completed correctly.

The Ferret website, which first broke the scandal, this week revealed that former Scottish Tory MP and shadow Scotland secretary Peter Duncan – a current trustee of SUAT – has lobbied Tory MSPs on behalf of his communications firm, Message Matters.

The Scottish Greens told the website that his positions as Holyrood lobbyist and trustee of a body funding the Scottish Tories were "not compatible".

Questions have also been raised over SUAT's status as an "exempt trust", with the Electoral Commission investigating whether a transfer of ownership of its Glasgow property disqualify it.

If so, the donations made to the Scottish Tories could be unlawful.

Urging the commission to conduct a full investigation, Wishart said fines would not be sufficient punishment for any wrongdoing, and called for "forfeiture of donations".

He added: "Serious questions are now piling up at Ruth Davidson’s door over the dark money that is funding the Scottish Tories.

"Ruth Davidson must come clean, and tell the public if donations from the Scottish Unionist Association Trust (SUAT) were funnelled into the election campaigns of Tory MPs John Lamont, David Duguid and Douglas Ross.

"The Scottish Tories must also reveal if the election expense returns of John Lamont, David Duguid and Douglas Ross were correctly completed.

"It’s time the Electoral Commission used its powers to crack down on rule breaking, cheating and dark money. If the commission find wrongdoing, we must see forfeiture of donations as well as fines – we think the scale and range of SUAT activity merits both sanctions."

SUAT gave £7500 each to Banff and Buchan MP David Duguid and Moray MP Douglas Ross last year, and donated to £5000 to Scottish Tory deputy leader Jackson Carlaw before he was an MSP.

The "dark money" criticisims come from the lack of transparency on the source of funding for donations made through SUAT.