DOUGLAS Ross has said he “doesn't know why” he didn’t declare more than £28,000 in salaries.

In an interview with Good Morning Scotland, the Scottish Tory leader blamed the undeclared cash on an “extremely bad” error which he said was his own fault.

He said he is now actively working with parliamentary authorities and that he is “extremely sorry”.

READ MORE: Douglas Ross 'sorry' and reports himself over £28,000 of undeclared salaries

The undeclared money was revealed in a Herald investigation in which the MSP and MP failed to declare 16 football matches totalling £7000 where he worked as a referee.

The Herald also reported the Moray MP failed to declare his salary as a Holyrood MSP, worth around £21,000 a year.

Ross said: “Yeah, it was a bad error on my behalf. I've obviously done it throughout the time of being an MP a bit.

"There's a period at the end of last year. I've tried to work out why I missed 16 games. I don't know why I did that.

"I noticed myself last week and I got in touch with the parliamentary authorities. I worked with him to get the register up to date.

"But you know, I am extremely sorry, this was a bad error. It was all of my own making, and I've tried to rectify it as soon as it came to light.”

The interviewer told Ross the SNP have accused him of being “knee-deep” in the Tory sleaze scandal.

He responded: “Well, I mean, the SNP will put their own spin on it. But I'm not trying to downplay the seriousness of this.

“It's a significant amount of money that should have been declared within 28 days that wasn't, and I am extremely sorry about that.

“I've tried as much as possible to rectify it as soon as I was alerted to do it myself by checking my own registers of interests.

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“I've worked with parliamentary authorities. And to show how serious I believe this is I've referred myself to the standards commissioner.”

Asked how damaging recent sleaze scandals has been to the Tory party, Ross said: “It's all damaging, of course, it is and it erodes the trust between the people who elected us and politicians, this has been an extremely difficult period for parliament for the Conservative Party, and for politics in general.

“And that's why I'm so disappointed that my own error has brought myself into this in but it's something I have to hold my hand up to I can't shy away from this, I made a mistake.

"It was a big mistake. It was an error on my part, no one else to blame. And I'm extremely sorry for that.”