Ronan Farrow reports at The New Yorker:
Last week, several news outlets obtained financial records showing that Michael Cohen, President Trump’s personal attorney, had used a shell company to receive payments from various firms with business before the Trump Administration. In the days since, there has been much speculation about who leaked the confidential documents, and the Treasury Department’s inspector general has launched a probe to find the source.
That source, a law-enforcement official, is speaking publicly for the first time, to The New Yorker, to explain the motivation: the official had grown alarmed after being unable to find two important reports on Cohen’s financial activity in a government database. The official, worried that the information was being withheld from law enforcement, released the remaining documents.
The payments to Cohen that have emerged in the past week come primarily from a single document, a “suspicious-activity report” filed by First Republic Bank, where Cohen’s shell company, Essential Consultants, L.L.C., maintained an account. The document detailed sums in the hundreds of thousands of dollars paid to Cohen by the pharmaceutical company Novartis, the telecommunications giant A.T. & T., and an investment firm with ties to the Russian oligarch Viktor Vekselberg.
There another 2000 words at the link!