A Boston man was indicted Wednesday in connection with a three-year, multimillion dollar fraud scheme.

Nathaniel Ponn was indicted on two counts of wire fraud and has been in custody since March 2016 when he was arrested and charged in a related criminal complaint.

According to court documents, it is alleged that from 2012 to April 2015, Ponn opened more than 400 brokerage accounts at nine investment firms throughout the United States, and used false names, Social Security Numbers, assets and income to open many of them. The companies allowed customers to transfer funds between financial institutions using an Automated Clearing House (ACH) transfer.

From February 2014 to April 2015, Ponn allegedly provided ACH transfer information to brokerage firms for accounts he opened on more than 350 occasions, totaling more than $8.5 million in attempted transfers. Each time, the bank account that Ponn allegedly provided did not have the sufficient amount of requested funds or in some cases did not exist.

Ponn was allegedly able to purchase securities totaling more than $2.7 million in accounts at eight investment firms through this scheme. When the firms found out the transfers had been rejected, they liquidated the securities in his accounts.

Ponn faces up to 20 years in prison, three years of supervised release and a fine of $1 million on each count of wire fraud.