Guldino da Silva, the Director of ANPM, told journalists on Thursday that laboratory tests would prove if the sample was oil or a remnant waste product.
Silva said several possible oil sites across Timor-Leste were under investigation.
This included new deposits in Suai - Ailembata, Same Betanu, Manatuto - Laklubar Soiba and in the west in Bobonaro.
"We have found many sources of oil in the south but continue to look across the country for new sources,” he said.
He said ANPM was confident the on-going oil exploration would produce “good results.”