The militants who barged into the Afghan home of Indian author Sushmita Banerjee and later shot her after asking why she wrote nasty things about them, the victim's in-laws told her Kolkata-based relatives on Saturday.

The slain author's younger brother Gopal Banerjee said her body was buried on Thursday morning as per Islamic traditions in Sharan city of Afghanistan's Paktika province.

"I managed to talk to my sisters' in-laws in Afghanistan over phone today (Saturday) around 2.30pm. I spoke to her husband Jaanbaz Khan and one of his cousins over Jaanbaz's mobile," Copal Banerjee said.

"He seemed very upset at what has befallen him. I could hardly talk to him. But I had detailed conversation with his cousin, who said the killers were Taliban militants," Banerjee said.

"The cousin told me that when the killers barged into the house, they started beating her. They were saying, "Why have you written all these nasty things about us?"

Sushmita Banerjee defied her family to marry Afghan businessman Jaanbaz Khan, with whom she fell in love in Kolkata. She stayed for years with him in Afghanistan, before coming back to India. In 1998, she wrote the best-selling memoir " Kabuliwalar Bangali Bou" (A Kabuliwala's Bengali Wife), offering a vivid description of the suffering of women under the Taliban.

Gopal Banerjee said: “The cousin told me that the militants tied up Sushmita's inlaws when they started protesting. They later abducted her."

Banerjee's bullet-riddled body, with some of the hair ripped off her head, was found on Thursday morning.