According to the AP:
The agency's civil rights chief sent a letter last month announcing the probe to the North Carolina chapter of the American Civil Liberties Union. The ACLU had coordinated a group of 57 complaints from people detained at the jail in 2009 and 2010.
The complaints include allegations that people were called racial slurs, not informed of their rights and forced to sign their names to documents.
The article quotes Phyllis Stephens, who is Wake Sheriff Donnie Harrison's spokesperson, as declining comment until they've seen the letter.
Read more: http://www.mysanantonio.com/news/article/AP-Newsbreak-Feds-probe-Wake-jail-on-immigration-1456006.php#ixzz1RQbGBCK6