The Nigerian military has seized 22 barges filled with stolen oil waiting to be ferried out of the restive Niger Delta region.
The barges full to the brim with crude oil were found by the joint military task force on a routine patrol, the officer in command said.
Soldiers fought off suspected thieves who tried to recapture the barges, Reuters news agency reports.
Oil theft has cost Nigeria billions of dollars in lost revenue over the years.
The barges are usually filled with oil from taps illegally placed in pipelines.
They then empty their cargo into larger ships, which go into international waters and offload their cargoes on to tankers.
The illegal loads are made to look legitimate with fake documents and sold on the open market.
The military says it has been clamping down on oil theft and according to Brig Gen Wuyep Rimtip, his men has seized 17 barges on a similar patrol last year.
Oil theft costs Nigeria an estimated $5bn (Ã‚Â£2.5bn) every year
Estimates of how many barrels of oil are stolen range from 70,000 to 500,000
Official estimates are made by subtracting the amount of oil delivered from the amount expected from a well head
Nigeria has proven reserves of over 31bn barrels
Its production capacity is 3.2m barrels per day
Its current production rate is 1.8m bpd
A crew of Philippine sailors were also arrested last year in connection with stealing oil.
President Umar Yar’Adua has said the trade in stolen oil is akin to the trade in “blood diamonds”, fuelling a conflict in the country’s oil-producing south and destabilising the government.
Estimates to the volume stolen annually range from tens of thousands to hundreds of thousands of barrels per day.
When oil prices were tipping at $147-per-barrel it was a multimillion-dollar-a-day industry.
Oil theft, known as “bunkering”, is connected to drug smuggling and gunrunning.
A number of armed militia groups operate in the Niger Delta.
Militants claim to be fighting for a better distribution of Nigeria’s oil wealth, but armed groups fund themselves with oil theft, extortion and kidnapping.