The man who has been called the "poster boy for greedy drug company executives" and "the most hated man in the world", Martin Shkreli, has responded to reports that a group of Sydney schoolboys made a drug that his company charges at $US750 ($A1011) a tablet.

Soon after the Fairfax Media report broke, people on Twitter started peppering Mr Shkreli with questions about the story.

Mr Shkreli's company gained the rights to Daraprim, an anti-parasitic medication listed by the World Health Organisation as essential, and soon after he raised the price from $US13.50 ($18) to $US750 a dose.