He was 56.
The best-selling writer, who penned both fictional novels and biographies of underworld figures, died on Monday.
Mr McKay grew up in Keith, Banffshire, before his family moved to Glasgow when he was a teenager.
He became a social worker and remained in the profession for 20 years, becoming director of social work with Argyll and Bute Council. He left to become a journalist and later wrote his first book, a collaboration with former gangster Paul Ferris which was published in 2001. Mr McKay had written to Ferris in prison to suggest that he act as a ghost writer for his story, The Ferris Conspiracy.
He went on to write books about gangland bosses Tam McGraw and Arthur Thompson, as well as serial killer Bible John, who terrorised Glasgow in the late 1960s.
In March, Mr McKay told how he had been diagnosed with cancer. At the time, he said: “If I have three months, three years or three decades, I’m living life to the full.
“Cancer doesn’t kill you – it’s giving up that’s deadly. That’s not for me.
“An occasional gangster has taken unkindly to what I’ve written about them and made serious threats.
“I didn’t let those get to me, so why should I let cancer bother me?”
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article