Former LAPD narcotics investigator Michael C. Ruppert — best known as an investigative journalist and peak oil awareness advocate — is dead. He was just 63 years old.

While details are sketchy, various sources say that he committed suicide. He recorded the final episode of his The Lifeboat Hour radio show Sunday (April 13), after which he took his own life with a self-inflicted gunshot wound.

Author Carolyn Baker, who was a guest on his show that evening, confirmed the news. “Sunday night, following Mike’s Lifeboat Hour radio show, he was found dead of a self-inflicted gunshot wound,” she wrote on her Facebook profile. “This was not a ‘fake’ suicide. It was very well planned by Mike who gave us few clues but elaborate instructions for how to proceed without him.

“It was my privilege to have known Mike for 14 years, to have worked with him, to have been mentored by him, and to have supported him in some of his darkest hours, including the more recent ones. I am posting this announcement with the blessing of his partner Jesse Re and his landlord, Jack Martin,” she continued. “Thank you Mike for all of the truth you courageously exposed and for the legacy of truth-telling you left us. Goodbye my friend. Your memory will live in hour hearts forever.”

In the mid-1990s, Ruppert worked as an LAPD narcotics investigator, before he experienced, first hand, government corruption. He uncovered evidence that pointed to the CIA being involved in drug dealing… and would publicly confront agency director John Deutch during a town hall meeting. Deutch did not handle the confrontation very well… and was ultimately terminated from the CIA as a result.

After his time with the LAPD, Ruppert went on to become an investigator and journalist, establishing a newsletter called From The Wilderness, a watchdog publication that exposed governmental corruption, including his experience with CIA drug dealing activities. The newsletter would evolve into a website under the same name, covering vast range of conspiracy theories, including international politics, peak oil, civil liberties, drugs, economics, and the nature of the 9/11 conspiracy.

In 2009, Ruppert starred in a documentary film by Chris Smith called Collapse, in which he summarizes current energy and economic issues, focusing mainly around the core concepts of peak oil and sustainable development… that ultimately lead to his belief of the imminent collapse of the world.

He’s also known for his 2004 book, Crossing the Rubicon: The Decline of the American Empire, in which he examines 9/11 and how it all pointed to oil. It’s available now at Amazon.com.

Earlier this year, VICE visited the man in the Rocky Mountains (where he had moved) and published a video series called “Apocalypse Man”, where he runs down the theories he’s discussed over the past two decades.