Nakamori has a 'half son' called Kaito.

***
Kaito x Conan!!!
***
Rumor had it that Nakamori Ginzo had an unofficial and unorthodox 'half-son'-brilliant, charismatic, and, most importantly, with the face that launched a thousand ships... one that looked exactly like Conan's.
Upon seeing this for himself, Conan made up his mind to never let go of Kuroba Kaito.
For Kuroba, who had already considered himself unlucky to cross paths with the famous detective Edogawa Conan-whom even criminals feared-things took a strange turn when (Nakamori-keibu) Inspector Nakamori's offhand remark landed him as a guest at the Suzuki and Kudo household.
Listening to Conan's constant "Kaito-nii" and "KID nii san," Kuroba felt the tension rise, his scalp tingling. Yet, in unspoken agreement, the two decided to silently help each other maintain their secrets during their three-day stay at the mountain villa. Kuroba, who thought he could avoid Conan forever after this ordeal, was soon defeated by the persistent little Tantei kun.
** Unlike Accomplice, Black Organization targets at Conan (like manga) not KID. Kaito is a nii-san there for Conan all the time.