New reports reveal Saudi Arabia sent a written warning about Tamerlan Tsarnaev to the U.S. Department of Homeland Security in 2012, long before Boston Marathon blasts, according to a senior Saudi government official with direct knowledge of the document.

It appears the Saudi warning came separately from the multiple red flags raised by Russian intelligence in 2011, and was based on human intelligence developed independently in Yemen.

Citing security concerns, the Saudi government also denied an entry visa to Tamerlan Tsarnaev in December 2011, when he intended to make a pilgrimage to Mecca, the source said.

Tamerlan Tsarnaev’s plans to visit Saudi Arabia have not been previously disclosed.

The Saudis’ warning to the U.S. government was also shared with the British government and it “did name Tamerlan specifically”, according to the source.

“It was very specific” and warned that “something was going to happen in a major U.S. city”. The document did not name Boston or suggest a date for his planned attack.

If true, the account will produce added pressure on the Homeland Security department and the White House to explain their collective inaction after similar warnings were offered about Tamerlan Tsarnaev by the Russian government.

A DHS official denied, however, that the agency received any such warning from Saudi intelligence about Tamerlan Tsarnaev.

And so the White House: “We and other relevant U.S. government agencies have no record of such a letter being received,” said Caitlin Hayden, a spokesperson for the president’s National Security Council.

The letter likely came to DHS via the Saudi Ministry of Interior, the agency tasked with protecting the Saudi kingdom’s homeland.

However, a Homeland Security official confirmed Tuesday evening on the condition of anonymity that the 2012 letter exists.

Meanwhile, House Homeland Security Committee chairman Mike McCaul plans to announce on Wednesday an investigative hearing to probe what U.S. intelligence knew prior to the Boston attacks.

Separately, President Barack Obama announced Tuesday that the U.S. government will launch a wide-ranging inquiry into the sharing of information among the Federal Bureau of Investigation, the Department of Homeland Security and other intelligence and law-enforcement agencies of the federal government.

The internal review will be led by Director of National Intelligence James Clapper and several inspectors general.

It is not yet clear whether information from Saudi Arabia will be involved in James Clapper’s inter-agency review.

Saudi Arabia sent a written warning about Tamerlan Tsarnaev to the U.S. Department of Homeland Security in 2012, long before Boston Marathon blasts

It appears the Saudi government alerted the U.S. in part because it believed American authorities should be inspecting packages that came to Tamerlan Tsarnaev in the mail in order to search for bomb-making components.

The written warning also allegedly named three Pakistanis who may be of interest to British authorities. The official declined to provide more details about the warning to the UK, but said the two governments received the same information.

The Ministry of Interior, he said, sent the letters in 2012, likely after Tamerlan Tsarnaev returned from Russia to the US in July.

President Barack Obama’s published schedule indicates that he met in the Oval Office with Prince Mohammed bin Naif bin Abdulaziz, the Saudi Interior minister, on January 14, 2013.

The Saudis denied Tamerlan Tsarnaev entry to the kingdom when he sought to travel to Mecca in December 2011 for a pilgrimage known as an Umrah – one that is undertaken during months that don’t fall within the regular Hajj period of the year.

That rejected application came one month before he traveled to Russia, where U.S. intelligence sources believe he acquired training enabling him to construct and detonate the bombs that he and his younger brother Dzhokhar placed hear the Boston Marathon’s finish line.

Dzhokhar Tsarnaev, 19, is in federal custody at a prison medical facility.

The Saudi official speculated that Tamerlan Tsarnaev’s residence in the US might have made it more difficult for him to gain entry into the kingdom.

“U.S.-based Muslims who become radicalized and want to visit Mecca create an unusual problem,” he said, compelling the Saudi government “to carefully examine applications”.

In the wake of the April 15 Boston Marathon bombings, Saudi Foreign Minister Prince Saud al-Faisal met with Secretary of State John Kerry on April 16, and then had an unscheduled meeting with President Barack Obama on April 17.

“This is the DNA of the Saudi government,” said the Saudi official, referring to officials in the royal court in Riyadh.

“This is how they work. They sent the letter, but that wasn’t enough. They then sent the top guy to meet personally with the president.”

The Saudi official dismissed the idea that Tamerlan Tsarnaev was likely trained by al-Qaeda while he was outside the US last year.

The Saudis’ Yemen-based sources, he explained, said militants referred to Tamerlan dismissively as “the volunteer”.

“He was a gung-ho, self motivated jihadi who wasn’t tasked by a larger group,” he said.

“There is no reason for anyone in Afghanistan to have in his thinking a scenario like this.

“He took the initiative. That’s why they call him <<the volunteer>>.”

“The Boston thing is beneath them,” he said of al Qaeda.

“They don’t think like this. This is like a firecracker to them. They want something big.”

Tamerlan Tsarnaev may have boasted about his plans online, the Saudi official said, offering an explanation for how Yemen-based sources first learned of him. Islamist militants have well-developed social networks that can enable news to migrate quickly across vast distances.

The Saudi government sometimes tracks such radicals by launching fake jihadi websites to attract extremists. The Ministry of Interior then tracks them electronically, often across the world, and shares information with governments it considers friendly, including the US.

The Saudi intelligence services have a long history of providing credible information to America and Great Britain about looming threats.

“This is the fourth time the Saudi Arabian government has given the U.S. specific intel” about a possible terror plot, the official said, citing prior warnings about Richard Reid, the so-called shoe bomber who repeatedly tried to light a fuse in his shoe to bring down American Airlines flight 63 bound for Miami in December 2001.

He also cited the 300-gram “ink-cartridge bombs” planted on two cargo planes headed for the US from Yemen in October 2010. Those explosives were intercepted in Dubai, and at an East Midlands airport in Great Britain.

Tamerlan Tsarnaev’s namesake was a 15-century Central Asian warlord who referred to himself as “the sword of Islam”. Sometimes spelled “Tamerlane” in English, he was known for his cruelty.

When he conquered Baghdad, Tamerlane reportedly made a pyramid of human skulls from unfortunate residents of that city.

Although still revered in Chechnya and throughout Central Asia, the original Tamerlane is sometimes vilified in modern-day Saudi textbooks.