The most recent Reuters survey of oil firms, OPEC officials and analysts showed Iran, the group's second-largest producer, pumped 430,000 barrels above its OPEC target in September, the most in absolute terms of any member.
"Iran has always been committed to crude production quotas set by OPEC and there has never been any violation by Iran in this respect," Khatibi said.
Khatibi said reports by the International Energy Agency (IEA) and other secondary sources are based on "guesswork and not reliable."
"The point to be noticed is that the figures reported by these sources are completely incompatible with one another."
OPEC agreed late last year to lower supply by 4.2 million barrels per day (bpd) as recession curbed fuel use and led to a slide in prices.
But the Reuters survey showed the group met 63 percent of promised cutbacks in September, down from 68 percent in August, continuing a trend of rising output that shows some members have relaxed adherence amid higher oil prices.
Iran has long been one of the group's members most interested in higher prices.
The world's fifth-largest crude exporter has struggled for years to develop its oil and gas reserves and now has to contend with an international lack of credit, as well as the U.N. nuclear sanctions over its disputed nuclear program.
SANCTIONS
A report by a parliamentary research center, published on Saturday by Iran's Aftab-e Yazd daily, said Iran's crude oil exports will "drop to zero" in eight years in the absence of an annual $4.5 billion in investment in the oil sector.
The authorities blame sanctions for the lack of foreign investment in the country's energy sector.
Iran also lacks sufficient refining capacity to meet its domestic demand and imports up to 40 percent of its gasoline requirements.
It subsidizes gasoline, which is therefore among the world's cheapest, encouraging fast growth in demand and making it very reliant on imports from international markets.
However, Iran's deputy oil minister Noureddin Shahnazizadeh said gasoline production had increased in the country.
"In the first half of the current Iranian year (starting on March 21) the refineries produced an average of 44.6 million liters of gasoline a day," said Shahnazizadeh, head of National Iranian Refining and Distribution Co., the Oil Ministry's website SHANA reported.
"We have produced some 600,000 liters a day more than projected plans … Currently the capacity of oil derivatives' stockpile in the country is around 9.7 billion liters."
To make Iran less vulnerable to international sanctions, Iran's parliament passed a bill in October to end energy subsidies. To become a law, the bill needs to be approved by the country's hardline legislative watchdog body, the Guardian Council.
Tehran says it will need an additional $6.5 billion from the budget through March to cover higher-than-expected import costs.
Iran has already been hit by three rounds of United Nations sanctions for defying to halt its sensitive nuclear work, which the West fears to be aimed at building bomb. Tehran says its purpose is to generate electricity.
(Writing by Parisa Hafezi; Editing by Sugita Katyal and Patrick Graham)
