diff --git a/mpt-witness-generator/witness/util.go b/mpt-witness-generator/witness/util.go
index 171a223dd7..f2adbb53d3 100644
--- a/mpt-witness-generator/witness/util.go
+++ b/mpt-witness-generator/witness/util.go
@@ -6,7 +6,6 @@ import (
 	"log"
 	"os"
 	"path/filepath"
-	"strconv"
 )
 
 func check(err error) {
@@ -15,33 +14,6 @@ func check(err error) {
 	}
 }
 
-func MatrixToJson(rows [][]byte) string {
-	// Had some problems with json.Marshal, so I just prepare json manually.
-	json := "["
-	for i := 0; i < len(rows); i++ {
-		json += listToJson(rows[i])
-		if i != len(rows)-1 {
-			json += ","
-		}
-	}
-	json += "]"
-
-	return json
-}
-
-func listToJson(row []byte) string {
-	json := "["
-	for j := 0; j < len(row); j++ {
-		json += strconv.Itoa(int(row[j]))
-		if j != len(row)-1 {
-			json += ","
-		}
-	}
-	json += "]"
-
-	return json
-}
-
 func StoreNodes(testName string, nodes []Node) {
 	name := testName + ".json"
 	path := "../generated_witnesses/" + name