Spark has appointed receivers to Mako Networks after the technology company was placed into liquidation last week.
Spark said it previously provided asset financing to Mako.
The phone and broadband retailer said it had set aside money for the amount it was owed, and it was comfortable with the carrying value.
Spark said it had a business relationship with Mako going back several years, which included leasing technology hardware to Mako.
"In early 2014, we showed our support to Mako by agreeing to a number of measures, including a debt restructuring and a repayment holiday for a period of two years, on debt owed by Mako to Spark," it said in a statement.
"Unfortunately, 18 months on, Mako's financial position has deteriorated to the point that Mako directors have decided Mako cannot continue normal business operations. It is disappointing to see an innovative New Zealand technology company struggle in this way."
Spark said it had owned the rights to the SecureMe service since 2014, which had been previously provided by Mako, and it therefore won't be impacted by the receivership.
The receivers are Brendon Gibson and Neale Jackson of KordaMetha.