A retired fraud investigator for the South Dakota Department of Revenue has pleaded not guilty to federal charges accusing him of targeting banks with nearly $150,000 in fraudulent wire transfer requests.

Steven Knigge, 69, faces charges including bank fraud and money laundering, the Rapid City Journal reported.  While working at the Revenue Department in 2015, Knigge is accused of asking banks in several states to wire money to an account in South Dakota belonging to him.

The banks received emails from someone purporting to be an account holder instructing bank employees to transfer money to a different account.

Authorities allege Knigge received more than $42,000 between two successful transfer requests from banks in Washington and Arizona to his accounts in Rapid City. They were among five requests Knigge allegedly made to out-of-state banks in July and August 2015.

After getting the money, Knigge made eight transfers mostly to Nigeria amounting to $30,400, according to authorities.

He also is accused of attempting to delete emails on his computer at the state Department of Revenue after IRS and FBI agents informed him in September 2015 that he was under investigation for fraud.

A woman who answered a telephone call from The Associated Press to a number associated with Knigge said he was no longer at that number. Knigge did not immediately respond to a Facebook message asking for comment.