St Barbara (ASX:SBM) subsidiary Simberi Gold filed an objection against the tax assessments by the Papua New Guinea Internal Revenue Commission (IRC), according to a Tuesday filing with the Australian bourse.

The IRC assessed a 152 million Papua New Guinean kina additional tax on revisions to Simberi Gold tax returns from 2017 to 2021 in relation to revisions to allowable capital expenditure, and applied penalties of 304.1 million kina, the filing said. The company and Simberi Gold identified alleged errors totaling 64 million kina.

The objection is now under review by the commissioner, according to the filing.

Shares fell past 1% in afternoon trade Tuesday.