After being interrogated and involved in an attempt at Funkspiel, he was shot four months later at the Tir national military firing-range in Brussels.

[5][6] After the General strike of 1941, Riek de Raat and Winterink moved in together,[5] hiding at their house at 8 Oude Looierstraat.

[5] In 1933, Winterink was one of three officials that ran the Netherlands branch of the International Red Aid, a social organisation that helped displaced communists with food and accommodation.

[7] At the time, Winterink and many others members of the CPN were involved in raising aid money to buy food and clothing for communist refugees from Germany.

Goulooze recommended Winterink, who was taken to Brussels where he was trained by Wenzel in Soviet wireless telegraphy procedures and ciphers.

[12][13] The most important members of the group were Maurice Peper who was the main courier between Winterink in Amsterdam and Jeffremov in Brussels, Adam Nagel and Wilhelm Voegeler who were radio operators along with Jakob Hillbolling, an agent who organised safehouse and accommodation and Hendrika Smith, the liaison to the Communist Party of the Netherlands.

On 18 or 19 August 1942 (sources vary), Winterink was arrested[14][15] by the Gestapo from the Sonderkommando Rote Kapelle, at a cafe in Amsterdam.