The Anti Corruption Bureau (ACB) on Monday questioned Chief Immigration Officer Masauko Medi and several other officers at Immigration office in Blantyre.
The bureau also conducted a search at Immigration Headquarters in Blantyre and residences of some immigration officials as part of investigations.
But ACB director general Reyneck Matemba said no arrests have been effected yet.
Matemba said bureau is undertaking some investigations.
He could not elaborate.