IN ONE of the more unusual side effects of negative interest rates, at least one Dutch household will be receiving, rather than paying, a mortgage payment from their bank.

In a ruling announced on Monday, the Netherlands’ consumer financial products watchdog, Kifid, said it had sided with the unnamed holders of the variable interest rate mortgage, who brought the case, rather than with lender Achmea NV.

The mortgage was denominated in Swiss francs, with a variable rate set at 0.7 per cent above Swiss Libor, a benchmark rate. When Swiss Libor fell below minus-one per cent in January 2015, the bank should have paid the mortgage holders around 0.3 per cent interest, Kifid said in the ruling.

Instead, Achmea had told the customers they would not be charged anything.

Achmea spokesman Stefan Kloet declined to comment on how many customers could be affected by the ruling, or for how many months. Achmea “has taken notice of the decision by Kifid,” Achmea said in a statement.

“At the moment we are studying their justification in greater detail.” The watchdog ordered Achmea to pay the customers back retroactively for the missed interest, and pay them 971 ($A1,455.12) in travel and legal costs.

Writing in Business Spectator last week, commentator Alan Kohler warned that negative interest rate policies (NIRPs) were “beginning to look counter-productive”.

“We may well look back ruefully on negative interest rate policy, or NIRP, from our post-apocalyptic dirt-floor humpies as one the greatest idiocies of the 20th and 21st centuries, up there with America’s sack and dump of Iraq in 2003 and 2011, the repeal of the Glass Steagall act and the Maastricht Treaty in Europe,” he wrote.

“Unless a miracle happens and the European and Japanese economic cadavers suddenly sit up and rub their eyes, central banks will eventually have to give up and admit defeat. The hope will be that not too much damage has been inflicted.

“But that is central banking for you, in the era of leverage: take from the savers and give to the borrowers in the hope that they will ‘do something’.

“Not so far, they’re not … they’re just punting it on real estate.”