The Hollywood Reporter, and later Fox News, are reporting the arrest.  From the Hollywood Reporter article, HERE, the lead paragraphs:

Conservative filmmaker Dinesh D’Souza, whose documentary 2016: Obama’s America took a critical look at President Barack Obama and was a surprise hit in 2012, will be arrested in New York on Friday for allegedly violating campaign-finance laws, The Hollywood Reporter has learned.

Federal authorities accuse D’Souza of donating more than is legal to the campaign of Wendy Long, who ran in 2012 for the U.S. Senate seat vacated by Hillary Clinton but lost to now-Sen. Kirsten Gillibrand. Long, though, is not mentioned in an indictment obtained by THR on Thursday.

Later reports indicate that D’Souza has been released after pleading not guilty to the charges.