After saying they had received no formal complaints about the "Roast Busters", police have revealed they received four complaints of sexual assault between 2011 and 2012.
Since 2011, police have been monitoring the Auckland group of 17- and 18-year-old men who have boasted online about sex with intoxicated girls, some of them underage.
A 15-year-old girl told television's 3 News on Wednesday that she complained to police two years ago of a sexual assault by members of the group when she was 13.
Now, police have acknowledged to Radio New Zealand's Morning Report programme they received a total of four complaints from girls aged 13 to 15 but are adamant they did not have enough evidence to prosecute.