The Commander of the Papua New Guinea Defence Force is looking into an unauthorised excursion of Indonesian soldiers into the country last week.
The newspaper, The National, reports that Brigadier-General Gilbert Toropo has directed his officers at the Vanimo Forward Base to submit a report on the matter.
Earlier Wutung villagers reported seeing eight armed Indonesian soldiers crossing the border.
PNG soldiers at the time were busy checking passengers and cargo from Indonesia at a checkpoint about 100 metres away.
Wutung councillor Raphael Tungla says the Indonesian soldiers passed the border monument on the beach and walked to the edge of his village.
He says they immediately turned back when villagers confronted them.
But Mr Tungla says he is concerned about the laxity of the PNG soldiers in manning the border.
He says soldiers should be patrolling the border and not checking passengers returning from the Batas market who had already been cleared by Customs, Immigration and the police.