After a year-long investigation an Anaconda nurse is facing more than 50 charges. Tisha Ann Brunell pleaded not guilty to accusations.

Now Brunell is being charged with four counts of felony sexual intercourse without consent, six counts of felony transferring of illegal articles, and 43 counts of misdemeanor unauthorized communications.

An internal investigation began shortly after Brunell was suspended in March, 2012.

Officials tell us Brunell was a licensed nurse working for the Community, Counseling and Correctional Services otherwise known as CCCS.

According to court documents the alleged crimes involve a total of three inmates. Investigators reportedly caught Brunell making sexually explicit calls and having inappropriate contact with the men.

NBC Montana spoke with the CEO of CCCS in Butte to find out more about the investigation.

"We have very strong protocols, policies, and procedures and frankly that's how we discovered what we believe was inappropriate behavior,” said Mike Thatcher.

“It wasn't voluntarily reported to us, we discovered it through phone conversations and we were able to record conversations at the START facility," added Thatcher.

Brunell is also accused of giving inmates tobacco, various drugs, and an iPod.