SDLP assembly member Dolores Kelly last night called for the PSNI chief constable to explain why more Catholics than Protestants have been arrested over the past five years.
The Policing Board member said she had written to Simon Byrne after figures showed that from 2016 to 2020, more than 57,000 Catholics were recorded as being arrested with almost 27,000 charged.
During the same period, around 31,000 Protestants were detained with under 15,000 charged, according to statistics released to investigative website The Detail.
Mrs Kelly said the figures have "rightly caused significant concern in our community".
"That Catholics and Protestants roughly make up a similar proportion of our population, but one side is twice as likely to be arrested than the other requires an immediate explanation at the very least," she said.
Mrs Kelly said she had written to the chief constable as "we need to get to the bottom of these figures and do all we can to address them".