Rent Smart Wales probe after landlord emails revealed
An investigation has been launched after details of hundreds of landlords who have not yet registered on a Wales-wide scheme were revealed.
Rent Smart Wales - aimed at raising standards of rented accommodation - contacted people who had started but not finished the registration process.
But the email addresses of recipients could be seen in the message.
Cardiff council, which handles Rent Smart Wales, said it is aware of an issue and it is being investigated.
Since November all landlords who rent out a property need to register with Rent Smart Wales by law.
The initiative was set up the Welsh Government to help tackle bad landlords who give the private rented sector a bad name.
It estimates there are 208,000 privately-rented properties in Wales, but only 65% had been registered by last November's deadline.
The email sent out told landlords: "We are writing this email to you as you have a started but not complete (sic) landlord registration with Rent Smart Wales."
Douglas Haig, director for Wales for the Residential Landlords Association, said: "We have long been warning of the need for greater security around the Rent Smart scheme to prevent this kind of error occurring.
"With landlords and letting agents expected to register by law, they need to have the confidence that their personal details will be handled sensitively.
"Whilst we are sure this was an innocent mistake and a simple case of human error, we would like to see measures put in place to ensure it cannot happen again."
A Rent Smart Wales spokesman at Cardiff council said: "Rent Smart Wales is aware that an issue arose on February 2, 2017 in relation to contacting customers.
"Rent Smart Wales and the City of Cardiff Council take data protection seriously. The matter is currently being investigated in line with the council's data protection policies."