Klaus Knefler is a German undercover agent working for the Allies. He appears in Medal of Honor: Allied Assault: Breakthrough. In the third mission, Klaus is seen donning a brown jacket similar to that of Major Grillo. He speaks in a deep German accent, and may sometimes phrase German words in times of panic. He holds a Beretta Pistol, though it is never used the first time you meet him. Klaus assists the player in getting to the Bizerte Harbour, but mentions that as Point Carriere. After going incognito, he wears a German desert officer's uniform. the player will follow him to a truck, wich the two use to get to the bizerte. there klaus will drive away from the player after dropping him net to a ship. after the player completes every goal, such as acquiring German plans and scuttling the ship, the player will progress though the harbor, to klaus, and a destroyed truck. when the player takes out all enemies in the area, klaus will comment that he is sorry, and that the truck must be abandoned, and that they must continue/escape on foot. What happens to him next is unknown, as he is not mentioned again in the game and the rest of the series.
In the first meeting with Knefler, he will die from one or two gunshots while he lockpicks a door. But later, in Bizerte Harbor he is invincible after the player interacts with him. a useful way to use his invincibility is to keep in cover as he is clearing the way.
This gets problematic, as a huge group of Germans armed with MP40's, Kar98s, and grenades will attack during the attempt to pick the lock. This is considered to be the hardest part of the mission (Bizerte Canal).