Reverend Lee Everett has also alleged police mistreated him when he was released from the bank during a police standoff with a suspect February 10.
The NAACP is looking into his claims, and the Wake County District Attorney's Office is reviewing what happened.
Everett is an employee of a Harris Teeter store near the Wachovia bank at 10050 Green Level Church Road where the hostage situation took place. Hostage taker Devon Mitchell, 19, let Everett go free about 45 minutes into a 3-hour standoff with police.
Mitchell was eventually killed by officers when he came out of the bank with what looked to be a gun pointed at the head of a hostage. It turned out there was no gun.
Everett told ABC11 Monday he understands officers were under pressure.
"We're dealing with men too that have a very dangerous job. Their job is dangerous," he said.
But Everett says that's no excuse for what happened to him when Mitchell let him go and he walked out the front door of the bank. He said he knew that Mitchell was not really armed.
"I looked at him really good, and I think that's the time I saw his hand move and it hit me, and I said that's not a gun," Everett recalled.
It was information Everett says he tried to tell officers, but couldn't because he was immediately thrown to the ground. He says he tried telling police he was a hostage as they shouted profanities and knelt on his back and head.
"The main word they used was 'shut up,'" he recalled "And I'm like "You're about to kill me. You're going to break my arm.'"
Everett says he was badly bruised and his shoulder muscles torn.
"It was way over the top," he said.
And Everett told ABC11 he suspects the treatment was possibly rooted in racism. He said he thinks police mistook him for the suspect because he's also black.
Everett has filed a formal complaint with the Town of Cary. The city is investigating his allegations along with the district attorney's office and the SBI.
"We take these complaints very seriously, which is why we have proactively referred it to the District Attorney's office and the State Bureau of Investigation to conduct an independent investigation into the allegations," said Town of Cary spokesperson Susan Moran in a statement Friday.
The local branch of the NAACP told ABC11 it's also looking at the case.
"Police misconduct is an issue - not only in Cary," offered Fred Foster with the NAACP in Durham. "Sometimes it takes the NAACP to step out and say, 'enough is enough, and we want somebody to do something about the situation.'"
The DA says he could have a decision on Everett's claims within a few weeks.