Marape issued the warning after discovering a sink filled with betelnut spittle. This was at the first floor of Vulupindi Haus at Waigani, Port Moresby.
He said most times, we tend to blame the buai sellers for the rubbish and buai spit all over the place but evidence proves otherwise.
Marape further called on Secretary for Finance, Dr Ken Ngangan, to get tough on staff who chew during working hours and terminate them.
Minister Marape also went on social media and made a statement regarding this issue.