Report of the split started over the weekend when a source told U.K.'s Daily Mail that Thurman was seen without her engagement ring during a recent event. "Uma and Arki (Busson) were due to attend a gala together on April 8, but Uma showed up without her engagement ring or her fiance. Arki was scheduled to attend and it seemed clear there was only one reason why he didn't show - because he and Uma are no longer an item," the source claimed.
"Uma lives in New York while Arki lives in London. He has been out and about without Uma since October when he went to a Halloween party alone. They have been at one or two events together, like Harvey Weinstein's pre-Bafta party in February, but on that occasion they looked miserable," another source added.
Prior to having a relationship with Busson, Thurman was married to Gary Oldman from 1990 until 1992. She then was married to Ethan Hawke, with whom she shares two children. Busson, meanwhile, also has two children from a previous relationship with Elle Macpherson.