DENVER -- A downtown Denver attack victim has accused a lead police detective of telling him to lie and say assailants cracked a tooth that was already damaged before the mugging.

The claim by the victim, Allen Andes, has spurred an internal investigation by the Denver Police Department and caused prosecutors to reduce second-degree assault charges against seven suspects in the attack to lesser a third-degree assault charge.

Andes claimed that lead Denver police Detective Paul Baca encouraged him to say the tooth was broken by the assailants when it wasn't, TheDenverChannel.com has learned from a source close to the investigation.

"We are aware of the issue and we're investigating it," police spokesman Sonny Jackson said Monday.

The Andes assault was among 26 violent attacks between July 17 and Nov. 17 in the popular downtown entertainment district.

In November, the Denver district attorney filed charges against more then two dozen people in the string of violent, racially motivated attacks.

An allegation of misconduct against the lead detective could be used by defense attorneys to challenge police credibility in all the downtown assault cases.

"I won't speculate on what impact -- if any -- this will have on this or any other cases," said district attorney spokeswoman Lynn Kimbrough.

Prosecutors had already decided to drop all charges against an eighth suspect, Rasheed Turner, before the victim changed his story, Kimbrough said.

Andes said he was attacked by about eight black males after leaving a Larimer Street bar about 2 a.m. on Aug. 23, 2009, according to court records.

As the gang pummeled him, Andes said a black woman shouted: "Get the white boy!"

His wallet containing $40 and a credit card was stolen, according to court records.

After initially saying his tooth was broken during the attack, Andes contacted district attorney's officials Feb. 25 and admitted the tooth was cracked before the attack, Kimbrough said.

"We immediately took steps to notify the defense attorneys in the case" the next day during a court hearing before Denver District Court Judge Edward Bronfin, Kimbrough said. "We also notified the Denver Police Department."

The victim also claimed that lead Denver police Detective Paul Baca encouraged him to say the tooth was broken by the assailants, TheDenverChannel.com has learned from a source close to the investigation.