A Conservative MSP has called for changes to the system under which complaints are made against politicians and investigated by a standards watchdog after being cleared of 19 complaints which he said were 'politically-motivated'.

Writing on Twitter today, Murdo Fraser, who represents Mid Scotland and Fife, and is his party's spokesman on Covid recovery, said all the complaints made against him had been dismisssed. 

"Just been advised by the Ethical Standards Commissioner that a further two complaints against me - both groundless and politically-motivated - have been dismissed. That is now 19 in the last 2 years, every one thrown out," he tweeted this morning.

"The system is being abused by those who wish to bully and silence opposition politicians doing their job of holding the Government to account. It has to change."

Mr Fraser did not say what the complaints made against him related to.

The Ethical Standards Commission investigate complaints about the behaviour of MSPs, councillors, and board members of public bodies as well as lobbyists, and also looks into how people are appointed to the boards of public bodies in Scotland.

The Commissioner is an independent regulator appointed by the Scottish Parliamentary Corporate Body, approved by MSPs and underpinned by legislation. The full-time post was created in 2013 and is currently held by Ian Bruce who was appointed Acting Commissioner in April 2021.

According to the watchdog's latest annual report, published in October last year, the commission received a total of 763 complaints about MSPs during 2020/21. It said 730 of the complaints related to a similar issue.

The total figure of complaints made was up from 109 the previous year. A total of 23 complaints were made to the watchdog relating to MSPs in 2018/19 and 28 during the previous 12 months.

The report stated: "Towards the end of 2020/21 the Commissioner received over 730 complaints relating to a similar issue.

"The majority of these complaints have been grouped together and will be processed in 2021/22. It is anticipated that concluding these investigations will require considerable resources.

"The rapid increase in complaint volumes in the past two years have been driven by single issues attracting a large volume of complaints. In 2019/20, we received 63 complaints about a single MSP’s manner of engaging with constituents. The complaints received towards the end of 2020/21 all related to a series of linked courses of conduct."

In March it was reported that the commissioner was probing claims an MSP leaked the conclusions of Holyrood's inquiry into the handling of allegations against Alex Salmond thereby breaching the MSPs' code of conduct.

A key focus of the commissioner was reported to be the source of information given to broadcaster Sky News days before a cross-party group of MSPs planned to report its findings.

Committee members were asked to hand over electronic communications - including text messages, WhatsApp messages and e-mails - as part of the probe.

Reports said it is believed the inquiry could take several months.

Sky News reported at the time that a majority on the committee had concluded that First Minister Nicola Sturgeon had misled parliament.

Former MSP Andy Wightman claimed in March on social media he believed an SNP member of the committee leaked the draft findings.

He wrote: "The vicious smears and lies spun by the SNP comms machine plus the timings of documents I circulated leads me to the conclusion that it was an SNP member of the committee who leaked these findings to the SNP media in order to spend the next four days trashing the committee."

The SNP responded: "No SNP member on the committee leaked anything from the inquiry - to suggest this to be the case is ludicrous and without a shred of foundation."

The Herald previously reported there had been a huge rise in complaints about MSPs to the Ethical Standards Commissioner in the wake of the inquiry.

A separate probe by James Hamilton, Ireland's former director of public prosecutions, found that Ms Sturgeon did not breach the ministerial code of conduct in relation to the inquiry.