The details emerging Monday on a trove of leaked Iranian intelligence documents drove home the depth of its influence in Iraq, where anti-government protesters have accused Tehran of meddling and overreach.

The New York Times and online publication The Intercept reported that the hundreds of documents from Iran's Ministry of Intelligence and Security painted a rich picture of the non-Arab country's clout in fellow Shia-majority neighbour Iraq.

Among the revelations in the reports was how Iran had recruited former CIA informants after the United States pulled out its troops in 2011, leaving the assets "jobless and destitute" and ready to share their knowledge.

And in one meeting between military intelligence officers from both countries, the Iraqi side had reportedly signalled to Iran: "All of the Iraqi Army's intelligence - consider it yours."

Iraq has had close but complex ties with its large eastern neighbour, whose sway among Iraqi political and military actors grew vastly after the US-led invasion of 2003.

The new reports served to confirm the sentiment of protesters across Baghdad and the Shia-dominated south who oppose the current government and its backers in Iran.

"Iran is intervening in our country," one demonstrator told AFP. "But we, the people, are the decision makers."

The demonstrator, a veiled Iraqi woman in her 60s, also greeted the fact that Iran had been hit by its own wave of protests since Friday, triggered by a sharp rise in petrol prices.

"The spark that started in Iraq has reached Iran," she said.

The New York Times and The Intercept said they had verified around 700 pages of reports written mainly in 2014 and 2015, received from an anonymous source.

The source had said they wanted to "let the world know what Iran is doing in my country Iraq".

The media outlets said the leaked 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".

Soleimani, the head of the Iranian Revolutionary Guard Corps' elite Quds Force, is Tehran's point man on Iraq and travels to the country frequently during times of political turmoil.

As Iraq faces its largest and deadliest protests in decades, Soleimani has chaired meetings in Iraq in recent weeks.

Copyright Agence France-Presse, 2019