A person in the country illegally racked up a medical bill of more than $165,000, which was later written off by a DHB.

Northland DHB recently wrote off about $335,000 as bad debt - the majority of which was owed by the one elderly patient.

According to the DHB, it did so after unsuccessful approaches to Immigration NZ and the relevant embassy for help, and deportation was ruled out on humanitarian grounds.

The DHB declined to release further details.

Summary information obtained by the Weekend Herald under the Official Information Act, show the patient had been in the country illegally since a visa expired in 2012.