New York ( CNN ) -- Two American flags that were taken from the Brooklyn Bridge are now in the United States and are expected to be returned to the New York Police Department Friday , a law enforcement official tells CNN . The NYPD said they believe a pair of German artists took the flags and replaced them with two white flags late on July 21 , the official added . The white banners were spotted early in the morning on July 22 by construction workers . At the time of the stunt , many New Yorkers wondered whether it represented an act of terrorism or an anti-American statement . But the artists , Matthias Wermke and Mischa Leinkauf , said the replacement of the American flags with two massive white flags last month was nothing more than an `` art project '' by the two performance artists meant to deal with `` questions of historical legacy and art in the public sphere . '' The investigation into the incident is ongoing , and it 's still unclear what , if any , charges the artists will face , according to the official . The artists dubbed the project `` White American Flags , '' saying that `` like an empty canvas , White American Flags invites many readings , multiple interpretations and projections . '' Wermke and Leinkauf also stressed they `` were careful to treat the bridge and the flags with respect and followed the U.S . Flag Code . '' `` White American Flags '' was meant in part as a tribute to the German-born American architect of the Brooklyn Bridge , John August Roebling , who left Germany in 1831 `` in search of a better future in the land of freedom and opportunity , '' the artists ' statement said . As part of the investigation after the switch , intelligence analysts looked into any possible significance of the day that was chosen to see whether that would yield clues . The date turned out to be the 145th anniversary of Roebling 's death . The Brooklyn Bridge opened in 1883 and at that time was the longest suspension bridge , according to the New York City Department of Transportation .
Two U.S. flags taken from Brooklyn Bridge expected to be returned to the NYPD later . The NYPD believes a pair of German artists replaced the flags with two white flags . Two white flags were spotted by construction workers the morning of July 4 . The investigation is ongoing and it 's unclear what charges , if any , the artists will face .