after in-vitro fertilisation technology had developed, making importation and quarantining of live breeding stock unnecessary. World War I internment camp During World War I the island continued to be used for quarantining animals but was also used for an internment camp which imprisoned about 300 "enemy aliens". Prisoners during this time included many German prisoners of war and suspected Danish imposter Hjelmar von Danneville. Other "enemy aliens" included German residents of New Zealand who were considered dangerous or who were reservists in the German or Austrian armies, sailors who had been at sea when war broke out, Germans from Samoa and musicians in a German band. In April 1916 there were 246 prisoners on the island, of whom 94 were military and 152 were civilians, and by May 1918 there were 314 internees. In March 1915 two prisoners escaped from the island by swimming to Petone, and in July 1918 four men escaped on a raft made of wood with oil drums for buoyancy, landing at Ngauranga. An inquiry was held towards the end of the war into numerous accusations of mistreatment of alien internees on the island. After the war ended the island reverted to use as a quarantine station. World War II internment camp On 29 August 1939 Matiu / Somes island was handed over from the Health Department to the Army and again shifted from quarantine station to internment camp, with the first group of internees arriving in December 1939. Internees included German and Italian residents of New Zealand and men from Pacific Islands plantations. By January 1942 there were also 45 Japanese internees who were New Zealand residents and fishermen from Suva. Tensions developed amongst the various national groups, in particular between German Nazis and German Jews. As in World War 1, there were allegations of ill-treatment of the men on the island. Three men escaped in November 1941 in a boat stolen from the island's caretaker and made it to the Akatarawa hills before hunger forced them out to buy food and they were rearrested. In 1942, the island was fortified with heavy anti-aircraft gun emplacements on the summit, but they were never used. This whole area was levelled flat for the purpose of this construction, with the result that was removed from the island's previous overall height. A degaussing station was built to provide protection for ships against magnetic mines. Many of the physical