Four years ago, the Tkhilaishvili brothers were running a pizza shop in Taunton. But the entrepreneurial immigrants from the former Soviet republic of Georgia thought they could make even more money, perhaps even billions, in the business of suboxone clinics, the health care centers where some of the state’s most desperate drug addicts seek treatment.

The brothers were convicted in federal court in Boston last month on extortion charges in a case that was marked by death threats and references to Russian organized crime. But industry insiders say it also illustrated the little-known underbelly of the drug addiction treatment business, where laypeople with no experience in health care can open a clinic and financially benefit from the state’s opioid epidemic.

“If you’re a businessman, this is a business opportunity,’’ said Dr. Hilary Smith Connery, clinical director for the Division of Alcohol and Drug Abuse at McLean Hospital, an affiliate of Harvard Medical School.

David Tkhilaishvili, 37, and Jambulat Tkhilaishvili, 47, who have managed two clinics in Quincy with the help of willing doctors, were convicted of using threats of violence to try to push out a co-owner of one of the centers, Allied Health Clinic.

The brothers’ lawyers had argued they were guilty of nothing more than a business dispute. Once the verdicts were announced, the men were immediately taken into custody and held without bail pending their sentencing, which is unusual in federal court and suggests they could be sentenced to serious prison time.

The case demonstrated just how easy it is for anyone to open a clinic, according to industry insiders who spoke to the Globe. All one needs is a cooperative doctor who is licensed to prescribe suboxone — a painkiller used to treat opioid addiction, in part by relieving withdrawal symptoms.

Patients who are addicted to opioids can be referred to such clinics, where they see a doctor who prescribes suboxone for use at home. The clinics should also have counselors to meet with patients to discuss their addiction and rehabilitation.

Suboxone clinics, like any other health clinic, make money by charging patients and their health insurance providers, such as Medicare, the public health care program.

The clinics are licensed by the state Department of Public Health, though the oversight of them varies. They are treated as general clinics, so it is difficult to say how many suboxone-specific clinics exist in the state.

Anyone who applies to run a clinic is subjected to a suitability review, which includes an inspection of the premises and a review of the operational plan. Depending on what types of services are being offered, the Department of Public Health may also set requirements for staffing, supplies and equipment, and laboratory services, according to people familiar with the industry. Doctors who are licensed to prescribe suboxone — there are roughly 1,850 in the state — are subject to separate regulations by the US Drug Enforcement Administration, and the state Board of Registration in Pharmacy.

But there appears to be little regular oversight over the business operation of the clinics, and who is involved.

“There is real potential that folks who want to make some money can do this, without putting in the resources or infrastructure to do it well,’’ said one person who works for a suboxone clinic management company who requested anonymity. “It really opens your mind to how many physician practices are out there, which may be well-meaning or may not be well-meaning.’’

The Tkhilaishvili brothers opened Allied Health Clinic in Quincy with Victor Torosyan, a car repairman from Watertown who invested hundreds of thousands of dollars, according to court records.

In an application for the clinic license, Torosyan, who now runs the clinic, wrote that he was the operator of a car repair shop and had once worked for a medical transportation company. Jambulat Tkhilaishvili had worked for the same medical transportation company in 2006. Kenton Fabrick, the administrator of the clinic, previously worked as a “winery marketing and social media guru.’’

David Tkhilaishvili was not listed on the application for the license for Allied Health Clinic, according to state records, though he was listed on the business’s financial records as a partner.

David Tkhilaishvili has been accused of questionable practices in the management of Davis Health, another suboxone clinic that he managed from late 2013 to early 2014. Dueling lawsuits were filed in Norfolk Superior Court by David Tkhilaishvili and Kurt Fabrick, a doctor and business partner in that clinic. The suits contain allegations of improper Medicare billing and poor patient care, according to court records.

Tom Lyons, a spokesman for the Department of Public Health, said in a statement that the department has received no complaints about Allied Health “with respect to patient care since it was licensed in September 2015.’’

“Nevertheless, the current allegations against two members of the clinic’s management team are disturbing,’’ Lyons said. “We are monitoring this situation very closely and will take action quickly should it become necessary to protect patient health and safety.’’

Connery said in an interview that the suboxone clinic industry has boomed as suboxone has become a preferred method of treatment amid the state’s opioid abuse epidemic.

Connery said there is no prohibition against business-minded people operating for-profit health care clinics – investors look to run for-profit cancer treatment clinics, for instance – as long at the business operations do not interfere with the medical treatment.

But Connery added that regulators need to at least ensure that administrators of health care clinics do not get involved in the medical operation. “If they’re making clinical decisions they’re not allowed to make, that’s an issue,’’ Connery said.

At the same time, she said, government agencies that oversee health insurance providers such as Medicare should also ensure that patients are receiving a full range of treatment services, such as counseling and drug testing, and that companies are not skimping on services that they bill for.

“Are patients walking in and getting no treatment at all?’’ she asked.

Milton Valencia can be reached at Milton.Valencia@globe.com. Follow him on Twitter @MiltonValencia