Some workers signed up to Kiwisaver are being stung by their employers who are paying them less or stipulating in their individual contracts that the employee and employer contribution will be deducted from their pay rather than paying it themselves.

According to Labour Minister Trevor Mallard, this practice is unethical as the employer is still receiving the government tax credit of 20 dollars a week per employee enrolled in the Kiwisaver scheme.

"Employers are getting a tax credit of $20 a week, which will fully compensate for the one per cent employer contribution for employees who are on a salary of up to $104,000," he said.

Since 1 April, employers have been required to match the employee contribution to their Kiwisaver account, usually one or two per cent.

However, there have been cases where this contribution is not occuring.

Mallard said he was looking into whether refusing to pay breached the Employment Relations Act good faith requirements and was considering setting rules to stop this from happening.

Unite's advice to workers in this situation is to make it clear to the employer that the payment is compulsory and to contact the union if there are any issues.