About half of heterosexual people diagnosed with HIV last year were in late stages of the virus

Otago University AIDS Epidemiology Group figures show 95 people were diagnosed in New Zealand, last year - the lowest figure since the early 2000s.

Twenty-six people were infected heterosexually.

Group leader Dr Sue McAllister says late diagnosis means they hadn't had antiretroviral treatment to control progression of their infection.

She says early diagnosis means people can get treatment - for their health, but to also stop transmission.

Effective treatments follows a theory that if HIV can't be detected, it can't be transmitted.