Scotney Williams, from Tenancy Management Services, knows of at least one Dunedin landlord who received a warning notice after a tenant illegally downloaded a copyrighted file.
"My view is if there is potential for harm, why do it? It's just a waste of time,"he said when contacted.
Under a law introduced in September, notices are sent via internet service providers to internet account holders if the owner of the copyright detects an infringement - for example someone has downloaded a song or a movie without paying the copyright holder for it.
Three such notices received in relation to the same copyright rights owner within a nine-month period has the potential to see the internet account holder, rather than the person who downloaded the material, brought in front a Copyright Tribunal and liable for up to $15,000.
The landlord concerned is now considering not including internet access in future tenancy agreements.
Mr Williams said landlords would not want to be involved in something that could end up with them having to pay for what a tenant had done.
Those who had already signed agreements with tenants that included internet access had few options to protect themselves, other than changing the agreement by consent with the tenant, or asking for the tenancy to be terminated, he said.
Otago Property Investors' Association president and landlord Grant Roydhouse said the impact on landlords had not been discussed by the association specifically, but was definitely something that needed to be brought to members' attention.
Many landlords in Dunedin included internet access as part of their rental agreement, particularly in studio accommodation for students.
As the law was in such an early stage, it was difficult to know how it would work, he said. It would be interesting to see in the first relevant test of the law, who would be held liable for any fine - the person who used the computer to download the material, or the person whose account it was.
"It is a situation that is in its infancy, but it's certainly something to keep an eye on."
The Ministry of Economic Development says where liability falls will depend on each case, and may have to be contested at the tribunal, but internet civil rights group Tech Liberty NZ believes the law clearly says the account holder is liable.
Both say ultimately the argument will be tested at the Copyright Tribunal and possibly in court.
New Zealand Property Investors' Federation national president Andrew King, of Auckland, said he had not been aware of the implications for landlords either, but agreed landlords should be considering it.
Since the law was introduced, many large organisations have increased their firewall and protection systems to block illegal downloading.
Internet service provider Unifone, which holds the account for the Dunedin City Council's free Wi-Fi in the city centre, sought legal advice on its position under the new law and did a lot of research and development before putting in a system that had so far protected it from breaches of the new law, network manager Travis Baird said.
Its system blocked illegal downloads, included firewalls that prevent file sharing, blocked efforts to hide file sharing, and monitored sessions.
It also allowed users found to be involved in illegal downloads to be blocked.
They "must have done something right", as no-one had had to be blocked yet despite tens of thousands of people using the Wi-Fi, and Unifone had not received any warning notices under the new law, Mr Baird said.
If landlords wanted to be protected they should deal with internet service providers that had worked out such systems and could provide them for clients, he said.
The University of Otago also restricts certain internet traffic types - it does not permit the use of file sharing applications other than for legitimate educational or administrative purposes, and has not received any warning notices yet either.
Mr Williams said installing protective systems were an option for landlords, but it would depend on cost. He still favoured not providing access at all.
