In January 2019, the National Enquirer exposed Bezos' extramarital affair with Lauren, including text messages between them.
In the lawsuit, Michael claimed he suffered substantial harm as a result of Bezos' allegations, including an FBI raid at his residence in front of neighbours.
The lawsuit said he was a "dutiful brother and manager" to Lauren at the time of the leak. Bezos was yet to issue a statement on the lawsuit against him.
Last week, it was reported that Michael received a $200,000 payment from the National Enquirer for leaking intimate images and text.
Lauren, however, described her brother's lawsuit against Bezos as "baseless and untrue".
Her brother has denied his role in the leak, saying he is suing Bezos for unspecified damages "in an amount appropriate to punish and make an example of defendants".
Last week, in a further twist to Bezos' phone saga, The Wall Street Journal reported that Michael reportedly sold photos to the National Enquirer, which then published a controversial story about Lauren and Bezos' affair early last year.
"Federal prosecutors in Manhattan have evidence indicating Jeff Bezos' girlfriend provided text messages to her brother that he then sold to the National Enquirer for its article about the Amazon.com Inc. founder's affair, according to people familiar with the matter," the WSJ reported.
Bezos in February last year accused the publisher of National Enquirer, an American tabloid published by American Media Inc (AMI), of "blackmail" and "extortion".
Bezos' affair returned to news when The Guardian reported that it was "highly probable" that Saudi Arabia hacked Bezos' phone in May 2018, which the Saudi government has denied.
"It seems likely that Michael Sanchez is the primary source for the National Enquirer's story. It's also possible that Saudi Arabia may have hacked Bezos' phone, though that's not a certainty," reports The Verge.
To find out how the Enquirer obtained his intimate texts to Sanchez, Bezos engaged private investigators led by security consultant Gavin de Becker.
After the investigation was initiated, AMI, Bezos alleged, threatened to release more intimate photos and texts.
( With inputs from IANS )