Actor-filmmaker Kamal Haasan, who is currently directing portions of upcoming trilingual film "Sabash Naidu", is said to be filling in for the film's director, T.K. Rajeev Kumar, who is unwell and hospitalised."Rajeev is down with high fever. He has been hospitalised and he should back on the sets in a week. Kamal sir took over the reins of the project because he didn't want it to get unnecessarily delayed, because they are working on a tight schedule," a source from the film's unit told IANS.On Friday, when Kamal tweeted that he is directing a song in the film, rumours started spreading that he is ghost-directing the project."Kamal sir was just filling in for Rajeev. He's just directing a song that we're currently shooting," the source said.In the film, Kamal plays a RAW operative and the role is based on Balram Naidu, the popular character from 2010 Tamil film "Dasavatharam".Also starring Shruti Haasan, Ramya Krishnan, Brahmanandam, Saurabh Shukla and Roger Narayanan, the film is being simultaneously shot in Tamil, Telugu and Hindi.