Although Nigeria passed legislation last year establishing an independent body the to make sure that oil majors pay the necessary royalties and taxes, anti-corruption activists are saying the law is not strong enough to fully clean the industry.

Under the law – the Nigeria Extractive Industries Transparency Initiative (NEITI) – oil companies are required to disclose how much money they paid to the central bank based on annual production. The government must also report how much it received.

“The law is a good beginning, but it’s trying to solve a problem that has been entrenched for decades. We can only do our best and the law helps us in that way,” said Shehu Sani, a civil rights activist and NEITI board member.

But the NEITI says Nigeria is still not getting its fair share of revenues because no one knows exactly how much oil is being pumped. The metering system in place measures how much oil is exported, but not how much comes out of the ground in the labyrinthine creeks of the Niger Delta.

“We know how much the industry sells, but we don’t know how much they produce. There is a dark hole between the oilfield and the terminal,” said NEITI spokesman Waziri Adio.