A woman threatened her housemate with the police after discovering he was using her toothbrush for his genitals.

Woman's toothbrush shock

Woman's toothbrush shock

The woman, known only as Sarah from New Zealand, moved in to a house share with her partner and had noticed their belongings, particularly her toothbrush, were regularly being moved by somebody in the house when her and her boyfriend were out.

Wanting to get to the bottom of the story, the couple set up a camera in their en suite bedroom to find the culprit - in which they soon discovered their housemate had been using Sarah's toothbrush on his genitals.

Sarah told Nine.com.au: ''I initially didn't believe my boyfriend when he called me and told me.''

The couple then confronted the culprit who confessed that he had a toothbrush obsession.

She added: ''He was bright red, like a tomato, then I just went off.

''I said we had a video of the whole thing and we knew his girlfriend was using our stuff and said we were going to the police, moving out, telling the landlord.

''We asked if he had done it before, then he said - 'I have a toothbrush obsession'. What the f***.''