Iraq's investigation committee has identified the perpetrators of the November 26 drone attack on the Khor Mor gas field in Sulaymaniyah province as "outlaw elements" from alleged Iran-linked militia groups, with arrest warrants issued for some suspects, according to a statement released on December 3.

Khor Mor is one of the most important gas fields in Kurdistan and Iraq, operated by UAE-based Dana Gas to supply power plants in the region. The field's operators, UAE-based Dana Gas and Crescent Petroleum, have invested billions in developing Iraq's largest non-associated gas field — companies with their own troubled history with Iran over a failed gas deal that has cost Tehran billions in arbitration losses.

Crescent Petroleum, the largest shareholder in Dana Gas, has been in a long-term legal wrangle with Iran over debts, which culminated in a recent legal ruling handing over Iran's last oil headquarters, the NIOC House, in London. 

Iraqi Prime Minister Mohammed Shia al-Sudani endorsed the investigation findings. However, authorities did not publicly name the group responsible for what was the 11th attack on the facility from the same area in a bid not to enrage Tehran and its proxies in the country.

The committee found that two drones carried out the attack: one struck the field, and the other fell outside. Both drones were launched from areas east of Tuz Khurmatu district, south of the gas field. Debris has been secured for memory device analysis.

"Security agencies have begun collecting technical evidence to convict them and bring them to justice," military spokesman Sabah al-Numan said.

The investigation committee was chaired by the interior minister and included the National Intelligence Service chief, the Kurdistan Regional Government interior minister, and the Joint Operations Command, with technical support from representatives of the Popular Mobilisation Forces.

The committee issued six recommendations, including redeploying security forces in the eastern Salahuddin operations sector, replacing commanders in the area with "competent leadership", enhancing intelligence coordination between federal and regional agencies and installing air defence systems at the field.

The attack on November 26-27 sparked a fire in one of the storage tanks. It halted gas supplies to electricity generation stations in Kurdistan Region, according to the regional natural resources and electricity ministries.

Daily financial losses from the attack reached $7.41mn due to halted gas production alone, according to Eco Iraq Observatory. The investigation remains ongoing to identify all individuals involved in what authorities described as "a serious terrorist act targeting Iraq's sovereignty and economic resources". 

Local officials earlier pointed to Iran-backed militias as the likely source, acting against US interests in the region. Kurdistan Regional Government Deputy Chief of Staff Aziz Ahmad questioned on social media: "How many attacks must happen before the US government simply allows the KRG to purchase kinetic anti-drone equipment for us to defend our skies and critical infrastructure?"

The investigation committee notably included representatives from the Popular Mobilisation Forces (PMF), the umbrella organisation for predominantly Shia militias with close ties to Iran, raising questions about the inquiry's independence, according to several Kurdish outlets who were reportedly enraged by their inclusion.

Dana Gas and Crescent Petroleum, the Khor Mor operators, have been locked in a decades-long legal battle with the National Iranian Oil Company over a separate failed gas deal, a dispute that has cost Tehran billions to date after being dragged through the courts in what it claims is a politically motivated case.

In 2001, NIOC signed a 25-year contract with Crescent Gas Corporation to export 500mn cubic feet of natural gas daily from Iran's offshore Salman field to the UAE, with deliveries scheduled to begin in 2008.

The deal collapsed after Iran's government, under political pressure from hardliners, refused to supply gas despite Crescent investing approximately $300mn in infrastructure and NIOC spending over $1.5bn developing the Salman field.

Ultra-hardliner Saeed Jalili, then secretary of Iran's Supreme National Security Council (SNSC) under hardline President Mahmoud Ahmadinejad, is considered the staunchest critic of the deal. Several reformist officials accused Jalili of sabotaging the agreement due to personal grudges against liberal Oil Minister Bijan Zanganeh, who served in the Khatami and Rouhani administrations.

Crescent filed an arbitration in 2009 at the Permanent Court of Arbitration in The Hague. The tribunal ruled in 2014 that NIOC had breached its contractual obligations and, in 2021, awarded Crescent $2.43bn in damages. With accrued interest, the award reached approximately $2.75bn by January 2025.

Separately, Dana Gas won $607.5mn from NIOC for the same breach, covering only the first 8.5 years of the 25-year contract. Additional arbitration claims could raise the total damages sought to $18bn.

NIOC has not fulfilled its payment obligations. In 2024, a UK court ordered the transfer of NIOC House in London, a prestigious building on Victoria Street overlooking Parliament, to Crescent as a partial settlement. A Rotterdam office was earlier seized in 2022.

Experts estimate total costs to Iran, including legal fees and lost revenue from flared gas, exceed $7.25bn.