BOSTON — A Massachusetts mayor was arrested Friday on charges he conspired to extort hundreds of thousands of dollars from companies seeking to operate marijuana businesses, federal authorities said.

Fall River Mayor Jasiel Correia brazenly accepted cash bribes in exchange for issuing official letters needed to obtain a license to set up a pot business, authorities alleged. At least four business owners paid a total of $600,000 in bribes to the mayor, and he used the money to support a lavish lifestyle and cover mounting legal bills, they said.

"Without hesitation, Mayor Correia was extorting marijuana vendor after marijuana vendor," U.S. Attorney for Massachusetts Andrew Lelling told a news conference after the mayor's arrest. "It's striking the lengths he went to get the money, and the seeming indifference with how overt his activities were."

Correia's lawyer didn't respond to messages seeking comment Friday.

In one instance, Lelling said, Correia walked into a vendor's office and simply asked for $250,000 to issue one of the letters. Another time, Correia was paid $75,000 in cash while sitting in the backseat of a car. He promptly handed over a signed letter, according to Lelling.

Once a rising political star in Massachusetts, Correia has remained in office despite efforts to force him out amid his legal troubles. He was already facing charges on accusations that he stole investor funds to bankroll a lavish lifestyle. He has pleaded not guilty.

The latest investigation, which also involved agents from the FBI and IRS, highlighted the potential for abuse in Massachusetts' nascent retail marijuana industry, authorities said Friday.

Under state law, a so-called non-opposition letter is required to obtain a license to operate a marijuana business. The head of the local government issues the letters, which say that he or she has verified that the business is in a permissible zoning district.

Correia has issued at least 14 of the letters, including two for his current girlfriend's brother, authorities said. It was not clear if authorities were alleging that there was any illegal activity involved in the issuing of the letter to the brother.

"We're a little concerned," said Lelling. "Local mayors can be sorely tempted. That single letter can be the ticket to a very lucrative business."

State Inspector General Glenn Cunha said he hopes the indictment prompts state marijuana regulators to consider additional safeguards.

Massachusetts voters approved recreational sale of marijuana in 2016; the first storefronts opened last November.

Friday's indictment also details other accusations against Correia, who became the old mill city's youngest mayor when he was first elected in 2015 at age 23.

Authorities say the now-27-year-old also accepted cash payments and a Rolex watch from a property owner to approve permits for his commercial building.

He also had his chief of staff, who also faces federal charges, give him half of her salary in return for allowing her to keep her city job, prosecutors said. It was not clear if the staffer had a lawyer representing her who could comment on the case.

She and Correia are both expected to appear in court Friday afternoon, authorities said. Three other associates are also charged in the marijuana extortion scheme and will appear in court on another day.

In a strange turn of events this year, Correia was recalled by voters and then promptly reelected on the same night in March. He's also among three mayoral candidates in a primary election scheduled for Sept. 17.

Correia pleaded not guilty last October to a 13-count indictment charging him with defrauding investors and filing false tax returns.

Prosecutors say Correia collected more than $360,000 from investors to develop an app that was supposed to help businesses connect with consumers.

Instead, he allegedly spent more than $230,000 of the money on jewelry, designer clothing and a Mercedes as well as on his political campaign and charitable donations.

A trial on those federal charges is slated to begin Feb. 24.