The Prime Minister, Tuila'epa Sa'ilele Malielegaoi, ordered a Commission of Inquiry to look into the behaviour of Fiame Naomi Mata'afa, and three other MPs, La'auli Leuatea Polataivao Schmidt, Faumuina Wayne Fong, and Olo Fiti Vaai.
They are all members of the Opposition Fa'atuatua i le Atua Samoa ua Tasi, or FAST Party.
Tuila'epa said the MPs had been campaigning when they should have been in parliament.
But Fiame said she was not concerned by something that was "quite ridiculous really".
"I have yet to get the formal motion.