Several months ago, the vibe from the ongoing investigation into Russian interference in the 2016 election was that the main player to focus on was Trump senior adviser and son-in-law Jared Kushner.

Kushner may very well still be under intense scrutiny, given it took him three revisions to get all of his foreign contacts down on his security clearance paperwork.

All that aside, more recent reports turn the focus firmly to former Trump campaign chairman Paul Manafort.

As was revealed on Wednesday, the FBI conducted a pre-dawn raid on Manafort’s home, only a day after he’d sat before the Senate Intelligence Committee and answered questions, in late July.

Now, Bloomberg Politics is reporting that the Robert Mueller-led investigation has issued subpoenas for Manafort’s bank records.

Mueller’s team of investigators has sent subpoenas in recent weeks from a Washington grand jury to global banks for account information and records of transactions involving Manafort and some of his companies, as well as those of a long-time business partner, Rick Gates, according to people familiar with the matter.

The special counsel has also reached out to other business associates, including Manafort’s son-in-law and a Ukrainian oligarch, according to one of the people. Those efforts were characterized as an apparent attempt to gain information that could be used to squeeze Manafort, or force him to be more helpful to prosecutors.

To show just how broad the investigation has become, this is just one area. Others include looking at the foreign ties of former national security adviser Michael Flynn, who was forced to resign after three weeks on the job, and later registered as a foreign agent for Turkey. It is looking at the firing of FBI Director James Comey as possible attempts at obstruction, and it is looking into a decade of real estate deals between Trump and wealthy Russians.

Federal prosecutors in Manhattan were investigating Manafort earlier this year, examining allegations that he laundered money from eastern Europe into New York properties, according to two people familiar with the earlier inquiry. The Southern District of New York handed off their work to the special counsel’s team once Mueller was appointed, the people said.

Along with the real-estate inquiry, the special counsel has taken over a review of Manafort’s late filings to comply with the foreign-agent registration act, known as FARA, according to one of the people.

Another point to note, it was Manafort who actually informed investigators about the June 9, 2016 meeting at Trump Tower, between Donald Trump Jr., Manafort, and Jared Kushner, with a Russian attorney, based on the premise that she had information from the Russian government that would be damaging to Hillary Clinton.

It’s not just Manafort, alone, but investigators are also looking into his relationship with his former business partner, Rick Gates.

Rick Gates’s relationship with Manafort dates to at least 2006, when the younger man joined Manafort Davis, a consulting firm that re-packaged a pro-Russian Ukrainian politician as a leader friendly to the West. Eventually, Gates helped manage a Manafort-directed private equity fund called Pericles, which was supposed to invest in Ukraine.

Dmitry Firtash, a Ukrainian oligarch, invested $25 million in a real-estate venture started by Manafort a decade ago that subsequently attracted the attention of investigators. Now in Austria, Firtash has been charged in an unrelated case with paying bribes in India in violation of the Foreign Corrupt Practices Act. He is facing a Justice Department request for extradition to the U.S. in that matter.

Firtash’s attorney, Dan Webb, said, “My client is not in any way cooperating with the special counsel office on Paul Manafort or any other issue. Because of the indictment pending in Chicago, I will not make any other comment.”

And it doesn’t stop there.

The inquiry by the U.S. Attorney in Manhattan initially focused on a Manafort-backed business called CMZ Ventures, which sought to develop a luxury skyscraper on Park Avenue in 2008. The partnership received $25 million from Firtash, according to court records filed in a New York federal lawsuit. But the money was never invested in a project, and the firm was shuttered in 2009.

The plaintiffs in that CMZ civil suit, including the former prime minister of Ukraine, Yulia Tymoshenko, alleged the real purpose of the firm was to launder money through the U.S. financial system that Firtash had obtained improperly by skimming sales of natural gas to Ukraine.

And that’s where Manafort’s involvement gets sticky.

A federal judge dismissed the lawsuit after CMZ Ventures’ attorneys successfully argued that U.S. laws did not apply to gas transactions abroad.

Manafort’s very complicated past is coming back to haunt him in this investigation, and the prevailing question has to be, how does it all involve Trump or his campaign?