What is the closest relative to the northern hairy nosed wombat?

The closest relative to the Northern Hairy-nosed Wombat is the Southern Hairy-nosed Wombat, judging by their scientific names.

There are, in fact, three species of wombats which live in Australia. They are the Common wombat (Vombatus ursinus), the Northern hairy-nosed wombat (Lasiorhinus krefftii) and the Southern hairy-nosed wombat (Lasiorhinus latifrons).