Federal investigators in Pennsylvania and New Jersey scrutinized South Jersey Democratic power broker George E. Norcross III in 2016, going so far as to persuade a federal judge in Philadelphia to let them wiretap his cell and work phones, records show.

No charges emerged, and Norcross' lawyer on Tuesday showed reporters a Sept. 27 letter from federal prosecutors in New Jersey indicating that his client was not under investigation.

"You have inquired about your client George Norcross' status in connection with an investigation conducted in the District of New Jersey pertaining to the procurement of tax credits," they wrote to defense lawyer Michael Critchley. "Based on a review of the applicable law and evidence obtained during the investigation, we have concluded that no further action is warranted. Accordingly, this matter has been closed."

The letter was signed by First Assistant U.S. Attorney Rachael A. Honig and Assistant U.S. Attorney Lee M. Cortes, one of the prosecutors in New Jersey's Bridgegate corruption case.

The letter did not elaborate on the investigation mentioned, and  representatives from the agencies would not do so either. But in 2013, Norcross and his legislative allies played a role in overhauling the state's economic incentives program, paving the way for tax credits worth billions of dollars to companies that stay in or move to New Jersey.

A court filing obtained by the Inquirer and Daily News shows that U.S. District Judge Paul S. Diamond in Philadelphia approved the wiretaps for Norcross' cell phone and landline at Conner Strong & Buckelew, his insurance brokerage, for July 28 to Nov. 16, 2016.

The wiretaps were cited in a Sept. 17 letter that prosecutors sent to a person whose conversations with Norcross were overheard on the secretly monitored calls, a routine step in cases involving wiretaps. The so-called intercept letter, reviewed by the Inquirer and Daily News, was signed by U.S. Attorney William M. McSwain, the top federal prosecutor in Philadelphia.

The contents of both letters were first reported Tuesday by Politico.

It wasn't immediately clear why federal authorities sought the wiretap, and whether prosecutors in New Jersey and Pennsylvania were working together or on distinct investigations. Court filings suggest one case could have been opened as early as 2015.

In his statement Tuesday, Critchley downplayed the interest from the prosecutors. He said that Norcross was never questioned by agents or prosecutors, and that the agencies gave him written and verbal assurances that Norcross neither was nor is the target of an investigation.

"It is an unfortunate fact of life that people can draw scrutiny based on unknown allegations," his statement said. "Mr. Norcross thanks the government for letting him know that neither he nor anyone with whom he works did anything wrong, and that its work ended quickly and without any finding of impropriety. As he has for years, Mr. Norcross will remain focused on the renaissance of Camden and helping the city build a brighter future."

The lawyer also told Politico that he had spoken with Assistant U.S. Attorney Frank Costello, a prosecutor in the anti-corruption unit for the Eastern District of Pennsylvania, who "specifically confirmed, as he had previously about a week ago, that Mr. Norcross is not under investigation by his office."

A spokesperson for McSwain said the office would neither confirm nor deny the existence of an investigation.

For decades, the now-62-year-old Cherry Hill resident and chair of the board of Cooper Health System has been a driving economic and political force in Camden, across the state and region, and beyond.

He was honored this year as Drexel University's business leader of the year. For about two years, until 2014, he was a part-owner of the parent company of the Inquirer and Daily News. Some consider him the most powerful nonelected person in New Jersey politics.

Dozens of his favored candidates have won election to local and state offices. His brother Donald represents South Jersey in the U.S. House of Representatives.

Norcross faced earlier scrutiny from law enforcement. In the early 2000s, the New Jersey attorney general investigated him in connection with allegations of corruption in Palmyra. In 2006, then-U.S. Attorney Chris Christie took the extraordinary step of publicly rebuking the state Attorney General's Office, accusing prosecutors of bungling the Norcross probe so badly that he couldn't pursue an independent investigation.

That Diamond, the federal judge in Philadelphia, approved the wiretap requests suggests that prosecutors presented him with what he deemed to be sufficient probable cause to suggest that Norcross was connected to a crime they were investigating, said L. George Parry, a former federal prosecutor.

"You have to establish that you have probable cause that a crime is being committed and that you would obtain evidence of that crime by monitoring that phone," said Parry.

Under the 2013 change to New Jersey's incentives programs, the state Economic Development Authority has awarded billions of dollars in tax credits.

One of the chief goals was to spur development in the long-struggling city of Camden. Among the companies awarded the credits are Holtec, a manufacturer of nuclear reactors; the 76ers, which built a practice facility there; and the carmaker Subaru.

Conner Strong, the insurance brokerage where Norcross is executive chairman, and two other companies were awarded $245 million in tax incentives to build an office tower on the Camden waterfront. Norcross' brother, who was a state senator in 2013, voted in favor of the law.

Until this week, there were no public signs of investigations or allegations related to the tax credits. The first clue that Norcross had even been under scrutiny was the unusual letter in which prosecutors declared the matter to be closed.

"That's a new one to me," said Parry, the former prosecutor. "When we came up dry, or didn't feel like we had enough evidence, we would just close the file."