Life expectancy in AIDS-hit South Africa has shot up by six years to 60 over the past few years, thanks to life prolonging anti-retroviral (ARVs) treatment, a demographer said Thursday.

"The good news is that mortality rates are falling," Rob Dorrington, a University of Cape Town demographer who co-authored a recent Medical Research Council (MRC) report told AFP.

"To a large extent this can be attributed to the roll out of ARVs, it has been more extensive than it has been anticipated."

Around 11 percent of South Africa's 50-million strong population is HIV positive.

The MRC's new report shows a "considerable drop" in the rate at which people have been dying in South Africa in recent years.

It said the probability of a 15-year-old dying before reaching age 60 fell from 51 percent to 40 percent over the past six years.

"As a result the average life expectancy in the country has improved from a low of 54 in 2005 to 60 in 2011, an increase of six years," the report said.