Department of Homeland Security whistleblower Philip Haney, who spoke out against his own agency during the Obama administration, was found shot dead in California.

The Amador County Sheriff's Office said that authorities responded to reports of a man lying on the ground with an apparent gunshot injury near Highway 124 and Highway 16 in Plymouth.

Red State and Heavy said Haney had been missing since Wednesday, and that the gunshot wound was found in his chest.

'Upon their arrival, they located and identified 66-year-old Philip Haney, who was deceased and appeared to have suffered a single, self-inflicted gunshot wound,' said authorities, according to the Washington Examiner.

Philip Haney (pictured), a former Department of Homeland Security official who blew the whistle on the agency, was found dead Friday with a gunshot wound

'A firearm was located next to Haney and his vehicle. This investigation is active and ongoing. No further details will be released at this time.'

Authorities have not shared any further details as they investigate Haney's death, no arrests have been made and a motive has not been made clear.

Although the nature of Haney's death has not determined, a Fox News contributor suggested he was murdered.

'Somebody I deeply respected and considered a friend Phil Haney - a DHS whistleblower during the Obama Admin was apparently killed yesterday in Southern California. Pray for his family and pray they find the person who murdered him,' she wrote on Twitter.

Fox News contributor Sara A. Carter suggested shared condolences to Haney's family and suggested the former official was murdered

Sources said Haney, who formally retired in 2015, was recently in contact with top government officials about return to work with DHS. He was also engaged to be married.

Haney gained national attention after he called out the DHS under the Obama administration, of which he criticized for its handling of radical Jihadists and Islamic extremists, in 2016.

He would testify that DHS ordered him to delete hundreds of files pertaining to people with ties to Islamist terrorist groups and argued that several terrorist attacks in the U.S. could have been prevented if certain files were maintained.

'It is very plausible that one or more of the subsequent terror attacks on the homeland could have been prevented if more subject matter experts in the Department of Homeland Security had been allowed to do our jobs back in late 2009,' Haney wrote in an opinion piece for The Hill in 2016.

Haney (pictured) testified before the U.S. Senate Judiciary Committee in 2016 that DHS deleted hundreds of files about people with ties to Islamist terrorist groups

In regards to a thwarted terror attack on a Christmas Day flight to Detroit, Michigan, Haney recalled how Obama cast blame on DHS for not identifying the threat

'President Obama threw the intelligence community under the bus for its failure to 'connect the dots.' He said, 'this was not a failure to collect intelligence, it was a failure to integrate and understand the intelligence that we already had.'

He also called out the administration for prioritizing 'political correctness' over safety.

'I can no longer be silent about the dangerous state of America's counter-terror strategy, our leaders' willingness to compromise the security of citizens for the ideological rigidity of political correctness—and, consequently, our vulnerability to devastating, mass-casualty attack.'

Haney said the devastating 2016 Orlando Pulse Nightclub shooting and 2015 San Bernardino terror attack could have been prevented if DHS took the right precautions.

In a 2015 interview with Fox News, Haney said his and other DHS employees efforts were stalled after they were accused of unfairly targeting Muslims.

If not halted, he said, they could have prevented the San Bernardino attack orchestrated by Syed Farook and Tashfeen Malik that killed 14 people.

The couple could have 'very plausibly' been flagged to the security services over their connections to Deobandi Movement, and its sub-groups al-Huda and Tablighi Jamaat,' Haney said.

'Either Syed would have been put on the no-fly list because of his association with that mosque, and or the K-1 visa that his wife was given may have been denied because of his affiliation with a known organization,' he said.

At the time of Haney's testimony before the Senate Judiciary Committee, Republicans questioned former Obama-era DHS Secretary Jet Johnson about the allegations.

Sen. Ted Cruz asked: 'Was Mr. Haney's testimony that the Department of Homeland Security order over 800 documents ... altered or deleted accurate?'

Johnson replied he had 'no idea' and denied ever knowing who Haney was.

'I don't know who Mr. Haney is. I wouldn't know him if he walked into the room,' he said.

Red State and Heavy said Haney (pictured) has been missing since Wednesday and was not seen until he was found Friday

During that same year, Haney released his first book, See Something Say Nothing: A Homeland Security Officer Exposes the Government's Submission to Jihad' about his experiences in DHS.

He told the Washington Examiner through text that he planned on writing a sequel.

'The National Security Meltdown sequel will pick up right where SSSN left off,' he wrote.

'My intention is to have it ready by early-to mid-Spring of 2020 (just before the political sound wave hits), then ride that wave all the way to the Nov. elections.'

Haney became a founding member of the Department of Homeland Security in 2002 as a Customs & Border Protection agricultural officer.

He would go on to serve as an armed CBP officer before being promoted to its Advanced Targeting Team.

Haney specialized in Islamic theology and the strategies used by the global Islamic movement.