Who is the snitch in Tantei Gakuen Q? In the anime Detective Academy Q/Tantei Gakuen Q, at one point we learn that there is a snitch in DDS spying for Pluto/Meiosei.

At first we are led to believe that it is Hongou Sensei, but  later Hongou is loyal to DDS when they go to the cruise ship so he probably wasn't the spy.

Katagiri Sensei had been briefly kidnapped and impersonated in the events leading up to the finale, but IIRC she is not being impersonated for very long, ruling her impersonator out as the snitch.

Ryu hates Pluto so can't be the snitch. Unless Pluto had bugged him (there is no confirmation of this in the anime)

So who was the snitch/spy? I'm talking about the period between when Hongou Sensei came in to before Dan was kidnapped.
The so-called mole is the subject of much debate between the manga and anime canons... 

In the manga,


   The secretary, Shino Katagiri... or rather the Pluto/Meiousei agent masquerading as her. The real Shino had was kidnapped before Dan Morihiko. Luckily they find and rescue her. It's assume that she was kidnapped later on.


Additionally:


   Ryu was originally sent by Pluto/Meiousei as a spy/envoy (due to his status as the their of the organization) inside DDS, particularly to keep an eye on Dan Morihiko, but he later defects from Pluto/Meiousei. 


In the anime, 


   Sir Anubis is the one that initiated the kidnapping of Dan Morihiko. He apparently hat Ryu under surveillance, after tries to leave Pluto/Meiousei, tries to use Dan-sensei as a bargaining chip to get Ryu to return.