Karel Sedláček operated as Soviet contact in wartime Switzerland

By Harlan Pryce · August 9, 2026

British intelligence tracked Karel Sedláček as he served as a clandestine contact for the Soviet Rote Drei espionage ring in neutral Switzerland during the Second World War.

The catalogue entry for KV 2/1657 in the UK National Archives is brief, but it establishes a specific intersection of identity and intelligence. It describes a man named Karel Sedláček, a Czech national who operated under the alias Charles Simpson. According to the record, Sedláček served as a "contact of the Soviet Rote Drei espionage ring in Switzerland during the Second World War."

There is a curious duality to the name in the public record. Today, Karel Sedláček is known as a professional darts player competing in Professional Darts Corporation events, where he carries the nickname "Evil Charlie." It is a stark contrast to the other Karel Sedláček—the one documented in the Security Service's personal files—who operated in the shadows of neutral Switzerland while Europe was at war.

Charles Simpson

The entry for KV 2/1657 is not the file itself, but a catalogue description of a record held within the Personal (PF Series) Files of the Security Service. These files were the primary method by which the British intelligence apparatus tracked individuals of interest. The description explicitly links Sedláček to the Rote Drei, the Soviet intelligence network that operated out of Switzerland.

During the Second World War, Switzerland was a critical listening post. Because of its neutrality, it became a hub for diplomats, refugees, and intelligence officers from all belligerent powers. The Rote Drei, or the "Red Three," was the Soviet Union's primary apparatus for gathering intelligence on Nazi Germany and monitoring the Western Allies. Being a "contact" for such a ring implies a role that may have been more peripheral than that of a primary agent, but no less vital for the logistics of clandestine communication and the movement of people and information across borders.

The PF Series

Sedláček’s entry sits within a broader collection of "Other Espionage Cases" from the World War II era. When viewed alongside other entries in the KV series, the scope of Soviet penetration and the subsequent British monitoring become clearer. The catalogue entries for other figures in the same archive show a pattern of long-term surveillance and late-stage prosecution.

For example, the records for Harry Frederick Houghton (KV 2/4381, KV 2/4477, and KV 2/4482) describe a British clerk at the Admiralty Underwater Detection Establishment at Portland. Unlike Sedláček, who is listed as a wartime contact, Houghton is recorded as a "Soviet spy convicted of espionage in 1961." The files indicate Houghton had been spying from 1951 until his arrest, conspiring with an employee named Ethel Gee to pass classified material to the Soviet Union.

Then there is Arthur Alexandrovitch Adams (KV 2/3788), who is described in the catalogue as "one of the most important Soviet espionage agents known to have operated in North America." Adams entered the United States illegally in 1938 under business cover, eventually attempting to penetrate the American atomic bomb project in the 1940s.

These entries, though fragmented, show the gradient of Soviet intelligence activity: from the high-level strategic penetrations of Adams to the opportunistic theft of naval secrets by Houghton, and the regional operational contacts like Sedláček in Switzerland.

Rote Drei

The Rote Drei was notorious for its efficiency and its eventual collapse. The network provided Moscow with an abundance of data on the Third Reich, but it also drew the attention of the Swiss counter-intelligence services. By the mid-war period, many of the ring's members had been compromised or arrested, leading to a reorganization of Soviet efforts in the region.

Sedláček’s role as a contact likely involved the facilitation of meetings or the relaying of messages between the Rote Drei operatives and their sources. In the world of intelligence, a "contact" is the connective tissue of a network—the person who knows where to go and who to meet, but who may not necessarily be the one drafting the reports sent back to the center.

Other archives hold further references to this subject that remain unseen here. The National Security Archive at George Washington University maintains documents related to East European unrest prior to the 1956 Hungarian Revolution and other papers regarding the AHPN. The UK National Archives also lists the file KV 2/1657 specifically under the header of the Security Service's personal files, marking Sedláček as a person of interest to the British long after the war ended.

There is also a trace of Soviet activity in the industrial heartlands of the era. Records from the CIA Reading Room mention the Stachanov coal mine at Radvanice and the Gottwald Iron Works in Kralovo Pole, both dated 1951. While these records focus on industrial output and economic intelligence, they reflect the same Cold War obsession with Czech infrastructure and personnel that defined the era of Sedláček’s activity.

The catalogue entry for KV 2/1657 does not record if Sedláček ever faced prosecution, what happened to him after the war, or whether the alias Charles Simpson was used to facilitate travel across the Swiss border.