Tang Renjian, 61, is under investigation for "serious violations of discipline and law" by the Central Commission for Discipline Inspection (CCDI) and National Supervisory Commission, CCDI said on its website.
The term is CCDI’s typical euphemism for corruption.
The notice gave no further details.
It is uncommon for an official of Mr Tang’s rank to be placed under investigation without first being removed from the post.
He most recently appeared in public on May 15 at a conference on rural talent, where he gave a speech, according to a post on the Agriculture Ministry’s website.
Tang formerly served as governor of China’s western Gansu province from 2017 to 2020 before being named Minister of Agriculture and Rural Affairs, according to official biographies.