It looks like we have an answer for why Rep. Alexandria Ocasio-Cortez's chief-of-staff abruptly resigned on Friday; he's under federal investigation.

According to the New York Post, Saikat Chakrabarti - the architect behind AOC's meteoric rise from bartender to ball-buster, is being investigated in connection with two political action committees he founded.

The two PACs being probed, Brand New Congress and Justice Democrats, were both set up by Chakrabarti to support progressive candidates across the country. But they funneled more than $1 million in political donations into two private companies that Chakrabarti also incorporated and controlled, according to Federal Election Commission filings and a complaint filed in March with the regulatory agency. In 2016 and 2017, the PACs raised about $3.3 million, mostly from small donors. A third of the cash was transferred to two private companies whose names are similar to one of the PACs — Brand New Congress LLC and Brand New Campaign LLC — federal campaign filings show. -New York Post

As the Post notes, PACs are required to adhere to stringent disclosure rules, while the private companies Chakrabarti funneled money into are not.

According to a complaint filed by Virginia government watchdog group - the National Legal and Policy Center, Chakrabarti's LLCs appear to have been specifically designed to circumvent federal reporting requirements.

As noted by the Washington Examiner in March:

The cash transfers from the PACs — overseen by Saikat Chakrabarti, the freshman socialist Democrat's chief of staff — run counter to her pledges to increase transparency and reduce the influence of "dark money" in politics. Chakrabarti's companies appear to have been set up for the sole purpose of obscuring how the political donations were used. The arrangement skirted reporting requirements and may have violated the $5,000 limit on contributions from federal PACs to candidates, according to the complaint filed by the National Legal and Policy Center, a government watchdog group. -Washington Examiner

According to the Post, "Federal authorities are looking at new salary rules imposed by Ocasio-Cortez when she took office earlier this year, and whether they were put in place to let Chakrabarti dodge public financial-disclosure rules, according to sources."

Interestingly, the Harvard-educated Chakrabarti agreed to take a massive pay cut this year - taking in just $80,000, while the average pay for his position is $146,830. With a salary below $126,000, he was not required to disclose his outside income.

And now, he's under federal investigation.