Manipulation and control of matter at the nano- and atomic level are crucial for the success of nano-scale sensors and actuators. The ability to control and synthesize multilayer structures using carbon nanotubes that will enable to build electronic devices within a nanotube is still in its infancy. In this paper, we present results on selective electric field assisted deposition of metals on carbon nanotubes realizing metallic nanowire structures. Silver and platinum nanowires has been fabricated using this approach due to its applications in chemical sensing as catalytic materials to sniff toxic agents and in the area of biomedical nanotechnology for construction of artificial muscles. The electric field assisted deposition allows the deposition of metals with high degree of selectivity on carbon nanotubes by manipulating the charges on the surface of the nanotubes. SEM and TEM investigations revealed silver and platinum nanowires between 10 nm-100 nm in diameter. The present technique is versatile and enables the fabrication of host of different types of metallic and semiconducting nanowires using carbon nanotube templates for nanoelectronics and myriad of sensor applications. Further, nanowires can also serve as model systems for studying quantum size effects at these dimensions.