Hundreds of leaked Iranian intelligence reports reveal the depth of Tehran's influence in neighbouring, now protest-torn Iraq, The New York Times and The Intercept reported Monday.
The US newspaper and the online news publication said they had verified around 700 pages of reports written mainly in 2014 and 2015 by Iran's Ministry of Intelligence and Security, and sent to The Intercept anonymously.
The secret source, who had declined to meet with a reporter in person, had said they wanted to "let the world know what Iran is doing in my country Iraq".
Iraq has close but complicated ties with both Iran, its large eastern neighbour, and the United States, which opposes Tehran's influence in the region.
The documents "offer a detailed portrait of just how aggressively Tehran has worked to embed itself into Iraqi affairs, and of the unique role of General (Qasem) Soleimani," wrote the outlets.
Soleimani, the head of the Iranian Revolutionary Guard Corps' elite Quds Force, is Tehran's point man on Iraq and travels there frequently during times of political turmoil.
Amid Iraq's largest and deadliest protests in decades, Soleimani has chaired meetings in Baghdad and Najaf in recent weeks to persuade political parties to close rank around Iraqi premier Adel Abdel Mahdi, sources have told AFP.
In one of the Iranian leaks, Abdel Mahdi is described as having had a "special relationship" with Tehran when he was Iraq's oil minister in 2014.
The prime minister's office told AFP it had "no comment" for the time being on the report.
The reports also named former prime ministers Haider al-Abadi and Ibrahim al-Jafari as well as former speaker of parliament Salim al-Jabouri as politicians with close Iran links.
According to the NYT, Tehran was able to gain much more access following the withdrawal of US troops from Iraq in 2011, which it said left Iraqi assets of the Central Intelligence Agency "jobless and destitute".
They then turned to Iran, offering information on the CIA's operations in Iraq in exchange for money, the report said.
In one incident, an Iraqi military intelligence officer had travelled from Baghdad to meet with an Iranian intelligence official in Iraq's holy city of Karbala.
During the three-hour meeting, the Iraqi official said his boss, Lieutenant General Hatem al-Maksusi, had told him to pass on the message to Iran that "all of the Iraqi Army's intelligence -- consider it yours".
Al-Maksusi had also offered to give Iran information about a covert system established by the US to eavesdrop on Iraqi phones, run by the premier's office and military intelligence, the reports said.