MANILA - (2nd UPDATE) Commission on Higher Education (CHED) Executive Director Karol Mark Yee resigned Wednesday after allegedly enduring months of harassment and death threats since his appointment to the agency.

"I have been at the receiving end of unceasing harassment and of relentless threats against my life and person, which has caused me great personal and psychological strain, that has ultimately made it exceedingly difficult to further proceed," he said.

Yee, in his resignation letter obtained by ABS-CBN News, however did not say who was troubling him.

His resignation came weeks after CHED Chairperson Patricia Licuanan stepped down.

• READ: CHED chair quits, cites phone call from Palace

Yee submitted his resignation letter to Malacañang on January 30, 2018. It was received by the Office of Executive Secretary on the same day.

In his letter, he said there were "ongoing legal and political challenges" that prevented him from exercising his duty as executive director following his appointment in July 2017.

"Despite these circumstances, I have worked to the utmost of my ability, as is my sworn oath, to tirelessly support the programs of the President," he said.

Yee hoped that President Rodrigo Duterte, along with the agency's newly-appointed officer-in-charge Prospero De Vera III, can protect the commission from "destructive interests of a few."

• READ: De Vera named CHED officer-in-charge

He said these "destructive interests" of some unnamed individuals have constrained the agency from attaining its full potential.

Despite of what happened, Yee remained grateful to Duterte and his colleagues.

"Rest assured that I shall continue supporting the President's landmark initiatives and programs in higher education, as we forge on towards a more equitable, accessible, and quality higher education system in the years to come," he said.

Yee replaced Julito Vitriolo as executive director last year after the latter was ordered dismissed by the Ombudsman.

• READ: Ombudsman orders dismissal of CHED exec Julito Vitriolo

Vitriolo was dismissed after he was found guilty of grave misconduct and gross neglect of duty.

Licuanan, in an earlier interview, said that problems continued even after Yee's appointment, since Vitriolo was still occupying his former office.

The Court of Appeals, in August 2017, ordered that Vitriolo be reinstated as executive director of the agency.

Last Jan. 29, the appellate court released another order affirming its earlier decision.