(CNN) -- A former Harvard University student, who compiled world-class academic credentials by allegedly fabricating his own history and plagiarizing others' work, pleaded not guilty to all the charges against him Tuesday, according to a Massachusetts prosecutor.

At his arraignment in Woburn, Massachusetts, Adam Wheeler, 23, entered his plea against the 20 counts he faces, including larceny, identity fraud, falsifying an endorsement or approval and pretending to hold a degree, according to Middlesex County District Attorney Gerry Leone.

In a statement, Leone said Wheeler, of Delaware, is accused of falsifying transcripts that detailed an outstanding academic career at some of Massachusetts' finest institutions.

He was exposed after submitting applications and references for the Rhodes and Fulbright scholarships while a student at Harvard University in 2009, according to Leone.

A Harvard professor reviewing Wheeler's application for one of the scholarships noticed similarities between Wheeler's work and that of another professor. After comparing both pieces of work, the professor determined that Wheeler had plagiarized most of his application packet, Leone said. The university launched an internal investigation and began to look into Wheeler's file.

University officials discovered that Wheeler had fabricated recommendations from Harvard professors, college transcripts reflecting perfect grades and a résumé listing numerous books he had co-authored, lectures he had given and courses he had taught, according to the release.

While he was at Harvard, Wheeler won the university's Winthrop Sargent Prize in English and the Hoopes Prize for outstanding scholarly work, as well as a research grant, all with plagiarized submissions, Leone said.

"Not only was this defendant untruthful on his application to the University and his numerous scholarship applications, he is also alleged to have stolen over $45,000 in grants, scholarship and financial aid money awarded to him on applications and submissions of documents that were based on lies and reproductions of other people's hard work," Leone said.

Officials also discovered that Wheeler also had submitted false SAT scores and had fabricated transcripts from both the Massachusetts Institute of Technology and Phillips Academy in Andover, although he never attended either school, the prosecutor said.

Harvard officials also found that Wheeler had previously attended Bowdoin College in Maine, where he was suspended due to academic dishonesty, according to Leone.

In January, after leaving Harvard, Wheeler applied for an internship at McLean Hospital in Belmont, Massachusetts, "stating that [he] was taking the spring semester off from Harvard to work on two scholarly books," Leone said in the release.

Wheeler was turned down by the hospital after a background check revealed he had falsified documents, Leone said. At the same time, Wheeler also submitted transfer applications to both Yale and Brown universities, claiming to be an intern at McLean Hospital, according to the prosecutor.