"We apologise for any confusion or misunderstanding this has caused," a Google statement said.
Mr Modi figures prominently in the search alongside images of terrorists, murderers and dictators.
Other world leaders on the list include former US president George Bush and Libya's Muammar Gaddafi.
Other prominent Indians who come up in the search include Delhi Chief Minister Arvind Kejriwal, lawyer Ram Jethmalani, fugitive underworld don Dawood Ibrahim and Bollywood actor Sanjay Dutt who is serving a jail term in connection with deadly blasts in Mumbai in 1993.
"These results trouble us and are not reflective of the opinions of Google," the company said in its statement released on Wednesday night.
"Sometimes, the way images are described on the internet can yield surprising results to specific queries... We're continually working to improve our algorithms to prevent unexpected results like this," the statement added.
The internet firm said the result was due to a British daily which had published an image of Mr Modi with erroneous metadata.
The Google apology came after many Indian politicians and commentators expressed concern on social media platforms.