The media authority has launched an investigation into comments made by the controversial radio host Kyle Sandilands who described a Pakistani-born disabled child as a "spider baby".

The Australian Communications and Media Authority has confirmed it has launched an investigation following the comments made on air on his 2DayFM show last month in which Sandilands appeared to make fun of the child who has additional limbs.

Kyle Sandilands ... called a disabled child "spider baby". Credit:Getty Images

"I can confirm that an investigation is under way," spokeswoman Emma Rossi said.

A complaint by SackVileKyle, one of the groups that constantly monitor Sandilands, has gone directly to the regulator because the incident might be in breach of a licence condition imposed on 2DayFM in 2010 to protect children.