NEW YORK, May 12: Billions of dollars worth of Iraq oil was siphoned off through corruption or smuggling in last four years, a US government report obtained by the New York Times said on Saturday.

The Times said that report estimates between 100,000 and 300,000 barrels a day of Iraq’s declared oil production over the past four years is unaccounted for . Using an average of $50 a barrel, the report said the discrepancy was valued at $5 million to $15 million a day.

The Times said that the report does not give a final conclusion on what happened to the missing fraction of the roughly two million barrels pumped by Iraq each day, but the findings are sure to reinforce longstanding suspicions that smugglers, insurgents and corrupt officials control significant parts of the country’s oil industry.

The report also contains the most comprehensive assessment yet of the billions of dollars the United States and Iraq spent on rebuilding the oil and electricity infrastructure, which is falling further and further behind its performance goals.

Adding together both civilian and military financing, the report concludes that the United States has spent $5.1 billion of the $7.4 billion in American taxpayer money set aside to rebuild the Iraqi electricity and oil sectors.

The US has also spent $3.8 billion of Iraqi money on those sectors, the report said.

The report also covered alternative explanations for the billions of dollars worth of discrepancies, including the possibility that Iraq has been consistently overstating its oil production.