The star is said to have been surrounded by fans during an outdoor shoot for Ghanchakkar.
A source told the Hindustan Times: "Emraan was shooting over the weekend on the Eastern Express Highway. The shoot had the actor walking on the highway towards a car, getting in and then driving off.
"Some people spotted him and soon there was a crowd. In an hour's time, thousands of people had gathered. That further led to a traffic jam, thus halting all movement in the area.
"The movie is based in Mumbai, and [director] Rajkumar [Gupta] prefers shooting at real locations. Thankfully, they've already shot most of the day scenes, so they will now rework things to make it possible to shoot at night."
The film's production schedule is also rumoured to have accommodated lead actor Vidya Balan's wedding in December.
Hashmi has previously described celebrity news as "brainless".