Of the 13 security guards checked in Glasgow on the 17th April, just six were fully-compliant with licensing rules.
The SIA said that, because the operation was intelligence-led, the figures were higher than they would usually be.
Two guards were reported for working without a licence under Section 3 of the Private Security Industry Act 2001, while five more are subject to further investigation.
As with earlier checks across Scotland between November (when licensing became law) and February, the figures show that compliance remains an issue.
In November, just 11 of the 51 guards checked in a cross-country operation were compliant. Later that month, checks in Inverness found less than a third of door supervisors wearing valid licences whilst on duty. And, this February, info4security reported that half of those questioned in an SIA sweep on Glasgow did not have SIA licenses.
However, the SIA said a UK-wide operation over Christmas and New Year found a compliance rate of 94 per cent.
Public concern
During the latest operation, which took in eight separate sites, SIA investigators were joined by officers from Strathclyde police.
Chief inspector Brian Connel, a crime prevention officer with the force, said criminality in the security industry has been an area of public concern for some time.
“Joint working with the SIA provides new opportunities for us to pursue that criminal element and disrupt their activities. Future operations will continue to target those suspected of offences.”
Christy Hopkins, an SIA head of investigation, said, “We all share the same concern for maintaining public safety and SIA licensing contributes towards that. It is therefore imperative that security operatives are SIA licensed”.
He added that those deploying unlicensed guards could face prosecution.
