WASHINGTON >> As he often did, Dr. Robert C. Smith was hammering away at his bosses at the Food and Drug Administration in the most caustic of terms at ameeting to address his concerns about the approval of medical devices.

With seven fellow scientists seated behind him in support, Smith charged that managers “are not following the law, not following the science, not following FDA core values,” according to notes of the 2008 session. He glared at his immediate supervisor, who sat fuming in front of him.

Smith — radiologist, lawyer, frequent litigant and the man now at the center of a spying scandal at the FDA — is in some ways typical of that peculiar Washington phenomenon known as the whistle-blower: He pressed charges of government abuse, he battled with his bosses, and he was ultimately shown the door amid lawsuits and investigations.

But the New York-born doctor took his role to an extreme, according to former colleagues, scorning negotiations, making enemies of critics and papering Washington with complaints, which helped sow chaos at the agency. One co-worker compared his efforts to “a mutiny.”

Earlier this month, FDA officials came under fire from Congress after disclosures that they had launched a surveillance operation monitoring the emails of Smith and four other employees as they wrote to their lawyers, members of Congress and even President Barack Obama. Smith’s scorched-earth tactics had so unnerved his bosses that they, too, resorted to extreme measures, and the monitors ended up producing a sort of enemies list of 21 agency critics, including congressional officials, academics and journalists.

Some 80,000 pages of documents intercepted in the spy operation — many of them emails from Smith seeking help from scientists, politicians, reporters, academics and others — detail his campaign to expose what he claimed were harmful practices at the FDA. The documents, accidentally posted online by an FDA contractor, reveal a four-year process of estrangement between Smith and his bosses.

At first, FDA managers sought to appease him by restructuring his office, calling in mediators and pledging reforms. But he responded with more sweeping charges of wrongdoing, accusing agency officials and manufacturers of a criminal conspiracy to market unsafe devices. An outside consultant said his vitriolic attacks created a toxic workplace.

Smith stood to profit from his accusations: He and other disgruntled FDA scientists had filed a lawsuit, kept secret under court seal by law, against manufacturers of imaging devices. After discovering the suit through their surveillance operation, FDA officials began to suspect his motives. Those suspicions intensified when they learned that he had filed similar whistle-blowing lawsuits against two previous employers, Yale and Cornell.

Smith, 52, who left the drug agency in 2010 and is now working as a radiologist at a private practice in Great Neck, N.Y., does not apologize for his aggressive style. “I’m not the kind of guy who ever in his life turns a blind eye to things,” he said in an interview.

His concerns about the effectiveness of certain imaging devices for detecting breast and colon cancer are shared by some medical experts. But potential allies were driven off by his abrasive style.

“He got annoying, he got obstructive in nature,” said Dr. Carl D’Orsi, a mammography expert at Emory University who worked on an FDA review panel and also served as a consultant for a manufacturer. Fellow employees went further, complaining to the consultant that Smith was “disruptive,” “adversarial” and “confrontational.”

Staff members for three congressional committees that often criticize the FDA reviewed Smith’s complaints and chose not to pursue them. The inspector general of the Department of Health and Human Services studied his claim that the agency was violating the law in reviewing medical devices and concluded that he was wrong.

Smith maintains that many imaging devices do not work as advertised by their manufacturers, produce many false positives and subject patients to needless rounds of potentially harmful radiological testing. Moreover, he says they waste enormous amounts of federal Medicare aid.

His concerns are now getting another look: the Office of Special Counsel, which investigates whistle-blower grievances, found in a confidential review this spring that Smith’s allegations raised a “substantial likelihood” of serious problems and required a full review. That has triggered an investigation by Kathleen Sebelius, the secretary of Health and Human Services.

A graduate of Johns Hopkins University and Yale Medical School, Smith was a respected radiologist who set new standards for diagnosing kidney stones with groundbreaking research in the mid-1990s. Colleagues described him as both brilliant and bombastic, and he clashed with supervisors in his jobs on the medical faculties at Yale and Cornell.

He charged in lawsuits that both universities fraudulently billed Medicare for improper radiological services. The fraud claims were ultimately thrown out, but Smith won settlements believed to total several hundred thousand dollars over retaliation he said he endured for complaining.

Within two years of joining the FDA as a radiologist in 2006, relations began to turn acidic there as well, as he challenged the approval of more than a dozen imaging devices.

Meticulously organized, Smith would arm himself with reams of scientific data, internal emails, notes of conversations, and citations from FDA policy manuals and health statutes to make his case. Often, his language would be peppered with legal phrases honed from his days at Fordham Law School, where he completed a degree shortly before joining the drug agency.

He and eight colleagues accused agency managers of being too closely aligned with the medical manufacturers they regulated. They became known as “the FDA 9,” and Smith was clearly their leader, coaching them in disputes with bosses and recruiting them to join his legal challenges.

In the lawsuit he and six of the supporters brought in 2009, which was later unsealed, Smith’s group essentially accused the FDA and medical manufacturers of conspiring to approve faulty devices. They brought the multibillion-dollar suit under the False Claims Act, which allows whistle-blowers to collect up to 30 percent of any damages. They withdrew it last year after the Justice Department declined to support the case.

A month before the lawsuit was filed, an FDA biomedical engineer named Paul T. Hardy wrote an email to the group signaling both his displeasure with the agency and the prospect of large financial damages.

“They are all corrupt,” Hardy said of his bosses. “Just need to sue the hell out of the agency … get a couple cool mill and get out.” (He was fired in 2011.)

After their efforts at conciliation failed, FDA officials concluded that Smith would not be satisfied short of a complete rollback of certain radiological devices approved in the last decade. When Smith and other medical reviewers began demanding that manufacturers provide them with more clinical data about the safety of their products, FDA managers deemed the requests excessive. “Things were getting out of hand,” said Larry Kessler, a former top FDA official. “The reviewers were setting the bar far too high.”

Smith repeatedly approached lawmakers, sending out batches of late-night emails with huge files attached to demonstrate the FDA’s dysfunction. Some congressional staff members thought the FDA might be punishing him for raising complaints. But others found his confrontational tactics so damaging that they chose not to work with him.

Meanwhile, FDA officials themselves resorted to more aggressive tactics as the battles wore on. Four times, the agency went to the inspector general to seek a criminal inquiry into allegations that Smith illegally leaked confidential information, had a financial conflict or improperly recorded conversations. Each time, the inspector general turned the agency down.

Despite the setbacks, the FDA moved ahead with its surveillance program in April 2010.

“I never imagined in my wildest dreams that they were watching us second by second on our computers,” Smith said.

Three months after the surveillance began, a supervisor approached Smith in an FDA library and told him he was being placed on administrative leave for improperly downloading documents and would be let go at the end of his two-year contract.

Smith sent his allies one last email as an FDA employee.

Captured in the surveillance files, it read: “Just to let everyone know, 30 minutes ago I was placed on paid administrative leave and escorted from the building. I am not kidding around. Talk to you later.”