He joined the Special Operations Executive, section F, as a wireless operator in the rank of Lieutenant. On 1 August 1940 a motorboat attempted to land three Frenchmen, Clech, Tilly, and Victor Bernard at Carentec in Brittany but had to abort after coming under fire.
First mission
Clech became the radio operator of the AUTOGIRO network of Pierre de Vomécourt «Lucas». In Operation DELAY II Peter Churchill’s mission was to land four SOE agents on the French Riviera by submarine. On 26 February 1942 Churchill flew from Bristol to Gibraltar with two radio operators, Isidore Newman «Julien» for the URCHIN network and Edward Zeff «Matthieu» for the SPRUCE network, where they were joined by Marcel Clech «Bastien», radio operator for the AUTOGIRO network, and Victor Gerson «René», an SOE agent on a special mission to organise the VIC Escape Line. They travelled in HM Submarine P 42 “Unbroken” to Antibes where on the night of 21 April 1942 Churchill took Newman and Zeff and their radios to the shore by canoe, and led them to their contact Dr Élie Lévy. Churchill then returned to the submarine and dropped off Clech and Gerson by canoe at Pointe d’Agay near Fréjus before returning to the UK. Arriving in Lyon in early May, Clech learnt that Pierre de Vomécourt, the organiser of the AUTOGIRO network, had been arrested on 25 April. His mission was then modified and he was sent to Tours, where he was assigned to the MONKEYPUZZLE network of Raymond Flower «Gaspar». He worked there from 3 August. On the night of 14 April he was brought back to London by Lysander, piloted by Henri Déricourt.
Second mission
Clech became the radio operator of INVENTOR network of Sydney Jones «Élie», with Vera Leigh «Simone» as courier. On the night of 14 May 1943 he was brought by Lysander piloted by Henri Déricourt with Sidney Jones and Vera Leigh to set up the INVENTOR network. Julienne Aisner accompanied them and became courier of the FARRIER circuit. The INVENTOR network was betrayed by double agent Roger Bardet, and on 30 October Vera Leigh was arrested. On 19 November Clech was arrested after his transmissions in Boulogne-Billancourt had been located by the German direction-finding service. Jones was arrested the next day. Clech was deported to Mauthausen concentration camp where he was executed on 24 March 1944. Leigh and Jones were also executed, Leigh at Natzweiler-Struthof concentration camp, Jones at Mauthausen.
As one of the 104 agents of section F who gave their lives for the liberation of France, Marcel Clech is honoured at The Valençay SOE Memorial, Indre, France.
