Superstar Rajinikanth, who flew back to Chennai after undergoing treatment at a Singapore hospital for nearly one-and-a-half months, is reportedly concerned about Dravida Munnettra Kazhagam (DMK) lawmaker Kanimozhi, who is languishing in Tihar jail in connection with the 2G spectrum allocation scam.

Rajinikanth on Thursday called up Kanimozhi's father and DMK chief M Karunanidhi and enquired about her.

"Rajini thanked Kalaignar (Karunanidhi) and enquired about his health and about Kanimozhi's well-being," said a DMK press release.

Kanimozhi is lodged at Tihar jail in New Delhi since her arrest on May 20 in connection with the 2G spectrum allocation scam.

Rajinikanth returned to Chennai on Wednesday night.

Rajinikanth was admitted to Intensive Care Unit (ICU) at Mount Elizabeth Hospital in Singapore for kidney ailment on May 28.

Earlier, he was admitted to Sri Ramachandra Medical Centre in Chennai on May 15. The Tamil actor was undergoing dialysis and had kidney problems.

Rajinikanth had been suffering from recurrent respiratory infection and gastro intestinal ailments and was advised complete bed rest.

The 61-year-old star with a god like fan following after the phenomenal success of Robot (Endhiran), which was dubbed in Hindi as well, had recently started working on his new film Rana with Deepika Padukone in Chennai.

He plays three roles in the film on the Mahurat sets of which he fell sick on April 29 and had to be hospitalized first.