Kuomintang, the MCP was able to operate more easily. Anti-Japanese sentiment among Malayan Chinese gave the party a great opportunity to recruit members and raise funds under the banner of defence of China. At this time, the party was infiltrated by an apparent British agent, Lai Teck, who became its Secretary-General in April 1939. Despite this severe security breach, the Party continued to operate effectively. By mid-1939 it claimed about 40,000 members, about half in Singapore. Structure The MCP was headed by a Central Executive Committee of twelve to fifteen members. About six of these were appointed to the Political Bureau (Politburo) which ran the party when the C.E.C was not in session. Each State had State Central Executive Committee and was in turn subdivided into several Districts. The smallest unit of organisation was the Party cell, which typically consisted of the members from one workplace or village. Large Party Congresses were held on an occasional basis. World War II On 8 December 1941, the Japanese Empire invaded Malaya. The British colonial authorities now accepted the MCP's standing offer of military co-operation. On 15 December, all left-wing political prisoners were released. From 20 December the British military began to train party members in guerilla warfare at the hastily established 101st Special Training School (101st STS) in Singapore. About 165 MCP members were trained before the British defences collapsed. These fighters, scantily armed and equipped by the hard-pressed British, hurriedly dispersed and attempted to harass the occupying army. Just before Singapore fell to the Japanese on 15 February 1942, the party began organising armed resistance in the state of Johore. Soon four armed groups, which became known as 'Regiments', were formed, with 101st STS trainees serving as nuclei. In March this force was dubbed the Malayan People's Anti-Japanese Army (MPAJA) and began sabotage and ambushes against the Japanese. The Japanese responded with reprisals against Chinese civilians. These reprisals, coupled with increasing economic hardship, caused large numbers of Malayan Chinese to flee the cities. They became squatters at the forest margins, where they became the main source of recruits, food, and other assistance for the MPAJA. The MPAJA consolidated this support by providing protection. O'Ballance estimates that in mid-1942 the regimental strengths were about 100 in the first Regiment, 160 in the 2nd, 360 in the 3rd, and 250 in the 4th. At this time a 5th, 6th, and 7th Regiment were