Six people received prison sentences Tuesday ranging from 3 to 10 years in the investigation of a local smoke shop franchise that made more than $5 million peddling synthetic marijuana before authorities raided the businesses, shutting down sales of a product marketed as “Mr. Miyagi.”

The federal probe spread wide, bringing indictments against four suppliers in Georgia and two local attorneys, one of whom killed himself just as his trial began earlier this year.

U.S. District Judge Elizabeth Foote sentenced Richard Joseph Buswell, one of the owners of the Curious Goods franchise, to 103 months in prison for selling a drug that has come to be seen as a major public health issue, with increasing reports of users becoming psychotic and sometimes dying from its effects.

Federal prosecutors said Curious Goods made about $5 million selling the synthetic drug over just 10 months in 2011.

“We clearly sold drugs and we broke the law with complete disregard to the people we were selling to,” Buswell told the judge before sentencing. “I don’t know where I got lost, but it started with drinking and drugs.”

Buswell’s 103-month sentence will be served in addition to a 126-month prison term he received in September in an unrelated investment scheme that cost a long list of victims more than $6 million.

Five Georgia men involved in the manufacturing and marketing of Mr. Miyagi also were sentenced Tuesday.

Drew T. Green and Tommy W. Malone, who owned the company that produced the chemical that gave Mr. Miyagi its potency, each were sentenced to 117 months in prison.

Boyd A. Barrow and Joshua Espinoza, who owned a separate company that used the chemical to make the leafy product for sale in the Curious Goods stores, received sentences of 70 months and 61 months, respectively.

Daniel P. Francis was sentenced to 42 months in prison for his role in helping develop a strategy to advertise and market Mr. Miyagi as potpourri when, according to prosecutors, it was clear the intent was to sell the product as a drug.

The six defendants sentenced Tuesday all pleaded guilty.

A federal jury in August convicted a seventh defendant, Lafayette lawyer Daniel James Stanford, who is set to be sentenced next month on charges of money laundering, conspiracy to distribute synthetic drugs and conspiring to introduce misbranded drugs into interstate commerce.

He was accused, among other things, of getting a cut of the drug proceeds in return for advising the Curious Goods stores on how to circumvent laws against synthetic marijuana.

Carencro lawyer Barry Domingue faced similar charges but died after he shot himself in April during his trial.

Federal prosecutors said the attorneys at one time advised Curious Goods to scrap incriminating advertisements after State Police visited one of the stores, including a radio ad stating “say nope to dope and word to legal herb” and signs that read “keep off the grass, get Mr. Miyagi.”

The attorneys also told Curious Goods employees not to sell smoking pipes or rolling papers to customers at the same time they sold packages of Mr. Miyagi, prosecutors said.

Follow Richard Burgess on Twitter, @rbb100 .