At the beginning of the "First Battle of Alamein", Rommel's DAK suffered an unexpected coup when they lost the signals intercept unit Nachrichten Fern Aufklarung Kompanie 621 (NFAK 621) which was commanded by the Hauptmann (Captain) Alfred Seebohm. This unit was overran and captured by the 9th Australian Division in an attack initially directed against the Italian "Sabratha" Division near the coast on 10th July 1942. Rommel when told of the unit's loss was furious--he had suddenly lost his best source of intelligence. They had provided him with an unparalleled wealth of tactical intelligence. This was "quite the most important intelligence coup of the entire North African campaign".
Rommel knew that his premier source of battlefield intelligence was gone. An avid consumer of signals intelligence, Rommel recognised that the nature of warfare in North Africa meant that ‘radio was the only possible form of communication — a medium as dangerous as it was valuable — and the British used it more carelessly than ever’. A large proportion of Rommel's "fingertip feel" rested on the efforts of this German intelligence unit. This was a superb unit operational and tactical.
They had provided to Rommel of vital information for his offensives since April 1941 "listening in" to British radio traffic, translating and interpreting and sending important signals direct to Rommel. To do this work, NFAK 621 included a team of highly skilled wireless operators and English language specialists with experience in intercepting British traffic from the French and Belgian campaign, and ‘therefore knew the weaknesses of the British radio system’.
Thankfully for Australians, NFAK 621 was not a heavily armed combat unit. Seebohm’s soldiers referred to themselves as the ‘Circus’ because of the unit’s ‘nondescript gaggle of buses and wireless lorries’. Many of these were civilian vehicles commandeered in France or elsewhere in Europe, and their non-military nature meant that Unit 621 looked quite unlike Panzerarmee Afrika’s other front-line units.
Australian attack caught the unit completely by surprise. They put up fierce resistance for over an hour while frantically trying to destroy documents, but was soon overrun. Most of the unit were either killed or captured, along with much equipment and documents. Very few escaped, and Seebohm died of his wounds some days later.