Google apologised by saying it is "sorry" after an identification programme in its new photo application tagged a picture of a black couple with a "gorillas" label.
"We're appalled and genuinely sorry that this happened," a Google representative said late on Wednesday in an email to AFP.
"We are taking immediate action to prevent this type of result from appearing."
Google apologised and immediately began fixing the problem earlier in the week after the offensive blunder was pointed out in a Twitter message from @JackyAlcine.
"Google Photos, y'all (messed) up," Jacky Alcine said in a series of emphatic messages.
"My friend's not a gorilla."
Other users also joined in to criticise Google for this blunder.
Google released its overhauled photo app for smartphones in May, touting it as a major advancement in sorting, organising, and handling pictures.
Google engineer Yonatan Zunger put the blame for the labeling on the artificial intelligence software designed to let machines learn how to recognise places, people and objects in pictures.
"Sheesh," Zunger said in the exchange of Twitter messages. "High on my list of bugs you never want to see happen. Shudder."
Zunger told of problems such as not seeing faces in pictures at all, or even identifying some people as dogs.
Picture recognition has proven challenging for computers and numerous companies are working on programmes to improve identification.
Google and Facebook are among Silicon Valley technology giants investing heavily in artificial intelligence to get machines to think more like the way people do.
"There is still clearly a lot of work to do with automatic image labelling, and we're looking at how we can prevent these types of mistakes from happening in the future," the Google representative said of the photo gaffe.
"I understand how this happens," Alcine said in the online exchange. "The problem is more so on the why."