New York (CNN) -- A professor at Princeton University took his life last week after a small group in his department demanded he be removed from his position, a longtime friend of Dr. Antonio Calvo said Friday.
"It was a mounted campaign against him," said Marco Aponte-Moreno, who last spoke to his friend in March.
Calvo was director of the Spanish Language Program and had worked at Princeton for 10 years.
Sophomore student James Williams called his professor "witty" and "sassy," "even controversial," but said that it was always in good taste.
"He was one of the best professors I've ever had. He was like one of us," Williams said.
Calvo had been under duress due to a review process that had dragged on since last year, according to Aponte-Moreno. The Spanish Department had recommended his reappointment, Aponte-Moreno said, but a small group within the department wrote a letter to the dean alleging misconduct which led to his abrupt suspension two weeks ago.
"They wanted him out no matter what," said Aponte-Moreno, adding that Calvo didn't know exactly what the accusations were in the letter, so he didn't have a chance to defend himself.
The university issued a statement on its website earlier this week announcing plans for a memorial for Calvo. The statement said that he was "on leave from Princeton at the time of his death."
Princeton University spokeswoman Cass Cliatt declined to comment further on the details surrounding Calvo's death, saying that it is the school's policy not to "speak to matters of personnel, which are not public."
"We are heartfelt in extending our condolences to his family, and we continue to offer sympathy and provide support to the many students and faculty who knew him and admired him. We, like they, are very saddened by his death," Cliatt wrote in an emailed statement.
Calvo died April 12 of multiple, self-inflicted "stab and incised wounds of the neck and left upper extremities of his arm," said Ellen Borakove, a spokeswoman for the New York City Medical Examiner's Office.
Students of Calvo's are planning to hold a closed forum Saturday at Princeton called "Justice for Calvo: Forming a Student Response."
"Everything happened so fast, this was his home," said Williams. "If he was treated unethically and unfairly, we need to address that issue and see that proper action is taken."