Beta Weapons are weapons that were not included in the game. It is also includes some weapons that didn't make it to the final game and weapons have their models changed. Many made well during development and it is unknown why they were removed. However, very most of them can be obtained through cheat device and trainers.
Grand Theft Auto 2
A weapon called the Microwave was removed.
A weapon called the Instant Vehicle bomb was also removed.
A weapon called the Electro Baton was also removed.