Iran has discovered one of its biggest oil fields with high quality crude in a southern province, the semi-official Mehr news agency quoted an official as saying on Saturday. "The preliminary studies show enormous crude reserves in this oil field, which can be considered as one of Iran's biggest fields," Mahmoud Mohaddes, Head of the Exploration Office at the State National Iranian Oil Company (NIOC) told Mehr. Mohaddes gave no further details about the field but said it was located in the country's southern border region. Oil Ministry officials were not available to comment. Iran is looking to discover 2.5 billion barrels of recoverable oil and 23 trillion cubic feet of gas in the course of the country's fifth five-year development programme (2010-2015) now under way. Iran, the world's fifth largest oil producer, has been hit by tightening international sanctions over its disputed nuclear work, which the West says is aimed at building bombs. Tehran denies this, saying it needs the nuclear technology to generate electricity. In the past months Iranian energy officials have announced exploration of new oil fields in various parts of the country to show that Iran had boosted its exploration activities in the absence of foreign companies.