Seven bipartisan members of the committee said Friday in a letter to Bezos that if the WSJ's reporting is accurate, then it would appear that Amazon intentionally misled Congress.

Shares were off 6.4% on the news, adding to the market's woes during a session where traders are scrambling to cash out on last month's propulsive gains before the next shoe drops.

The probe will require Amazon CEO Jeff Bezos to testify before Congress, something he has previously resisted.

Bezos is the only CEO of the American Tech "big four" (Amazon, Apple, Google and Facebook) who has never before testified in front of Congress.

Last night, Bezos told Amazon investors to "take a seat", and insisted that the company would continue to invest in its vast expansion plans despite posting disappointing results.