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diff --git a/src/Cech_complex/include/gudhi/Cech_complex_blocker.h b/src/Cech_complex/include/gudhi/Cech_complex_blocker.h
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+/*    This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+ *    See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+ *    Author(s):       Vincent Rouvreau
+ *
+ *    Copyright (C) 2018 Inria
+ *
+ *    Modification(s):
+ *      - YYYY/MM Author: Description of the modification
+ */
+
+#ifndef CECH_COMPLEX_BLOCKER_H_
+#define CECH_COMPLEX_BLOCKER_H_
+
+#include <gudhi/distance_functions.h>  // for Gudhi::Minimal_enclosing_ball_radius
+
+#include <iostream>
+#include <vector>
+#include <cmath>  // for std::sqrt
+
+namespace Gudhi {
+
+namespace cech_complex {
+
+/** \internal
+ * \class Cech_blocker
+ * \brief Čech complex blocker.
+ *
+ * \ingroup cech_complex
+ *
+ * \details
+ * Čech blocker is an oracle constructed from a Cech_complex and a simplicial complex.
+ *
+ * \tparam SimplicialComplexForProximityGraph furnishes `Simplex_handle` and `Filtration_value` type definition,
+ * `simplex_vertex_range(Simplex_handle sh)`and `assign_filtration(Simplex_handle sh, Filtration_value filt)` methods.
+ *
+ * \tparam Chech_complex is required by the blocker.
+ */
+template <typename SimplicialComplexForCech, typename Cech_complex>
+class Cech_blocker {
+ private:
+  using Point_cloud = typename Cech_complex::Point_cloud;
+
+  using Simplex_handle = typename SimplicialComplexForCech::Simplex_handle;
+  using Filtration_value = typename SimplicialComplexForCech::Filtration_value;
+
+ public:
+  /** \internal \brief Čech complex blocker operator() - the oracle - assigns the filtration value from the simplex
+   * radius and returns if the simplex expansion must be blocked.
+   *  \param[in] sh The Simplex_handle.
+   *  \return true if the simplex radius is greater than the Cech_complex max_radius*/
+  bool operator()(Simplex_handle sh) {
+    Point_cloud points;
+    for (auto vertex : sc_ptr_->simplex_vertex_range(sh)) {
+      points.push_back(cc_ptr_->get_point(vertex));
+#ifdef DEBUG_TRACES
+      std::cout << "#(" << vertex << ")#";
+#endif  // DEBUG_TRACES
+    }
+    Filtration_value radius = Gudhi::Minimal_enclosing_ball_radius()(points);
+#ifdef DEBUG_TRACES
+    if (radius > cc_ptr_->max_radius()) std::cout << "radius > max_radius => expansion is blocked\n";
+#endif  // DEBUG_TRACES
+    sc_ptr_->assign_filtration(sh, radius);
+    return (radius > cc_ptr_->max_radius());
+  }
+
+  /** \internal \brief Čech complex blocker constructor. */
+  Cech_blocker(SimplicialComplexForCech* sc_ptr, Cech_complex* cc_ptr) : sc_ptr_(sc_ptr), cc_ptr_(cc_ptr) {}
+
+ private:
+  SimplicialComplexForCech* sc_ptr_;
+  Cech_complex* cc_ptr_;
+};
+
+}  // namespace cech_complex
+
+}  // namespace Gudhi
+
+#endif  // CECH_COMPLEX_BLOCKER_H_