An Indian American was among those detained by the US police along with anti-war activist Cindy Sheehan and Beverly Young, wife of a Republican Congressman.
They were arrested at the time of President George W Bush's State of the Union Address to Congress.
The person, who did not want his identity revealed, was questioned by the police and authorities for close to an hour before being released. This was because he resembled someone on a Secret Service photo watch list, a media report said.
The man was a personal guest of Florida Democract Alcee Hastings at Bush's address last week and is said to be a prominent businessman from Broward County, Florida, who works for the Department of Defence and has a security clearance, Time Magazine said.
According to the report, the Indian American after sitting through the entire speech in the gallery was surrounded by about ten law enforcement officers as he was exiting the Chamber and taken to a room in the Capitol.
"For close to an hour the man, who was born in India but is an American citizen, was questioned by the Police, who thought he resembled someone on a Secret Service photo watch list", according to Capitol Police Chief Terrance Gainer.
{{/usCountry}}"For close to an hour the man, who was born in India but is an American citizen, was questioned by the Police, who thought he resembled someone on a Secret Service photo watch list", according to Capitol Police Chief Terrance Gainer.
{{/usCountry}}Eventually, the police realised it was a case of mistaken identity and let him go, the magazine said.
Gainer has assured Congressman Hastings that the Capitol Police, Secret Service and FBI will investigate why the man was detained for so long, and try to "sharpen our procedures.