Update via Reuters:  Five people were arrested and are in U.S. custody, charged in an insider trading scheme that generated more than $30 million in illegal profits, an FBI spokeswoman said on Tuesday.

The scheme, which ran for 5 years, involved traders who employed hackers to steal confidential corporate news releases.

On Tuesday, U.S. authorities revealed that they had broken up the insider trading ring, which raked in over $30 million in illegal profits, and are set to file criminal charges against 9 people, according to The New York Times.

Five Arrested In Insider Trading Hack Scheme

Hacking and insider trading combine in sophisticated scheme

The case is noteworthy because of the combination of hacking and insider trading. The first arrests were made Tuesday morning, and a press conference will be given in Newark. Top officials, including Jeh Johnson, secretary for Homeland Security, and Mary Jo White, chairwoman of the S.E.C., are expected to discuss the charges.

Prosecutors unsealed an indictment against 5 men on Tuesday morning. They are accused of hacking companies such as Business Wire, PR Newswire, and MarketWire in order to steal over 150,000 news releases before they were sent out to the public.

The scheme involved hackers based in Eastern Europe and U.S.-based traders, and generated tens of millions of dollars in profit. Authorities allege that the traders provided “shopping lists” of different kinds of news releases to enable insider trading. Among those companies targeted were Bank of America, Clorox, Caterpillar and Honeywell.

S.E.C. takes steps to protect sensitive business information

A similar case was filed in 2005, when the S.E.C. filed charges against traders based in Estonia, who were hacking Business Wire in a similar scheme. Although hacking news releases has previously been used to gain an illegal edge on the market, this latest scheme is far more developed than previous ones.

Last year, security research firm FireEye claimed to have uncovered a group of hackers known as Fin4, which attempted to infiltrate the email systems of pharmaceutical and financial companies to gain information about deals. FireEye shared the results of its investigation with the S.E.C. and the FBI.

The S.E.C. has previously asked a number of companies to share information about data stolen from their networks during cyber attacks, which may be used for insider trading. Similar requests have also been made of large public relations firms, according to The New York Times, which cites a person briefed on the matter but not authorized to speak publicly.