A mobile ad hoc network is a wireless network of mobile devices that communicate with one another without any fixed network infrastructure. Existing mobile ad hoc networks are either based on IEEE 802.11 a or b standard. Both standards provide limited bandwidth and therefore are not suitable for data-intensive applications such as automated video surveillance. Wi-Fi Direct is a new technology that enables mobile devices to directly communicate with each other without a wireless access point. Compare to existing technologies it provides data rates of up to 250 Mbps which is sufficient for several mobile data-intensive applications. Wi-Fi Direct technology, however, has two main limitations. It does not support communication between two client devices in a group and it also does not provide support for multi hop communication. This paper describes a Wi-Fi Direct based multi hop mobile ad hoc network. More specifically a routing layer has been developed to support communication between Wi-Fi Direct devices in a group and multi-hop communication between devices across a group. The proposed system has been implemented on a group of four Wi-Fi Direct enabled Samsung mobile devices.