[6] At the age of 14, Berry claimed to be fifteen years old in order to join the Merchant Navy and after an initial engagement at sea he sailed aboard the oil tanker Cymbeline on 27 May 1940 as a Boy Seaman.

[7][8] Sailing on behalf of the British Admiralty from Gibraltar to Trinidad, Cymbeline was attacked on 2 September 1940 by the German commerce raider Widder,[9] a merchant vessel converted into a heavily armed cruiser.

The tanker was sunk with loss of seven of the crew, although 26 survivors, including Berry, were rescued and taken prisoner of war being held aboard for 6 weeks before going into captivity in occupied France.

[9][10][11] Berry was held prisoner of war at Besançon and later Ilag St. Denis in France,[12] during which time he reportedly escaped from captivity and became a black marketer in Paris until he was recaptured.

[13] Unable to speak German he spent most of his time at the zoo although he claimed to have been frequently arrested for signalling to the bombers which were targeting Berlin by night.

[13] He was transported to Genshagen where he joined the other recruits Roy Courlander, Lewis, William Brittain, Frank McLardy, Martin and Alfred Minchin.

[12] In February 1944 the unit moved to Hildesheim at the base of the SS Nordic Study Centre, it numbered 8 men and from here the New Zealander Roy Courlander began visiting prison camps to try to recruit more members.

[23] On 22 March 1945 he was assigned with a handful of the recruits to join the 3rd Company of 11th SS Armoured Reconnaissance Unit which consisted of Germans, Dutch, Danish, Norwegians, Flemings, Swedes, Swiss and various foreign volunteers.

[26][27] From September 1944 when Roy Courlander was captured in Belgium by Allied forces and subsequently interrogated, Berry had been identified as a member of the British Free Corps.

[28] On 3 July 1945 and 3 November 1945 Berry was formally interviewed and gave full statements concerning his life, his capture and his time with the British Free Corps.