In summit meetings of leading countries (hereinafter referred to as "summit"), various issues are discussed on financial crimes such as money laundering, drug trafficking, international crimes by transnational organized crime groups, and terrorism, etc., emphasizing the necessity of international cooperation for their suppression. Since 1997, the conference of G8 Ministers of Justice and the Interior Meeting has been held every year, and at the meeting held in Moscow, Russia in June 2006, discussions were focused on support for measures against terrorism, cybercrimes, illegal immigration and drug trafficking.

  The Senior Experts Group on Transnational Organized Crime (Lyon Group) combating transnational organized crimes was established in 1995. At the Lyon Summit held in 1996, the Lyon Group presented the "Senior Experts Group Recommendations to Combat Transnational Organized Crime Efficiently (40 Recommendations of the Lyon Group)," concerning protection of informants and witnesses, and controlled delivery (monitored illegal transportation) etc. Discussions also have been held on the methods for investigation and regulations to cope with transnational organized crimes, such as smuggling firearms, drugs and humans, cybercrime, money laundering, corruption including bribery, etc. Since the multi-concurrent terrorist attacks in the U.S. in September 2001, joint meetings have been held with the anti-terrorism expert group (Rome Group). In May 2002, the "G8 Recommendations on Transnational Crime" stipulating counterterrorism measures was adopted by reviewing the "40 Recommendations of the Lyon Group," in addition to measures against transnational organized crimes.