Mallika Sherawat is in Chennai this week, as she has to shake a leg with STR aka Simbu for a special number in 'Osthi'. "The song will be shot in two to three days and will be completed within this weekend," sources say.

The number is the Tamil version of 'Munni...' of Bollywood's 'Dabangg', as 'Osthi' is the remake of the Salman Khan starrer. "A grand set has been erected on a popular studio in Chennai for the purpose," sources add.

Directed by Dharani, the film has Richa Gangopadhyay opposite Simbu, who is playing a carefree police officer. 'Jithan' Ramesh is doing a crucial role in the movie, which is expected to hit the screens at the earliest.

"Mallika has been signed for a hefty remuneration and the sets for the song have cost a bomb for the producer. On the whole, some crores are being spent on this single song," circles close to the unit say.