Scarlett Johansson dating 'Hangover' star Justin Bartha?

Scarlett Johansson has been linked to The Hangover Part II actor Justin Bartha.

Johansson, who split from Sean Penn in June, reportedly attended Bartha's performance in the play All New People on Saturday and joined the star for the cast dinner at New York City's Café Un Deux Trois.

Eyewitnesses claimed that the two spent most of the evening together, with an insider adding to Page Six that the pair were "completely engrossed" in one another.

The source said: "They seemed pretty fascinated with each other and only talked to each other. It looked sometimes flirty, but also they seemed to be involved in a deep discussion."

Bartha and Johansson were also apparently seen "flirting up a storm" at nearby bar Karaoke Boho later in the evening.

Reps for the two declined to comment on the matter.

Johansson was recently spotted on a "flirty" dinner date with her ex-husband Ryan Reynolds.

> Sean Penn 'moving on from Scarlett Johansson'
> Justin Bartha: 'Hangover II is dirtier'

Watch the trailer for The Hangover: Part II below: