The 34-year-old actor starred alongside Beharie in the Steve McQueen-directed film about a sex addict living in New York City. Beharie played a love interest for Fassbender's character.
Rumours of a romance have been sparked after the pair were spotted together in New York this week, with Fassbender's arm wrapped around Beharie's shoulders.
This is not the first time Fassbender has been linked to a fellow cast member. The Irish actor briefly dated Zoe Kravitz last year, after starring with her in X-Men: The Last Stand.
Fassbender recently said that lately he tends to pick his career over love, stating: "To be honest, relationships as a whole for me in this industry have been a difficult thing to maintain.
It goes with the territory. I would be prepared to walk away from relationships because of my job. I wanted to give this everything and go for it 110 per cent, so I guess my work has taken precedence over that."
Both Fassbender and Beharie have yet to comment on their alleged relationship.
The US theatrical trailer for Ridley Scott's Prometheus, which stars Michael Fassbender as an android in a crew of explorers, was released yesterday (March 17).
Watch the trailer for Prometheus below: