diff --git a/beacon-chain/core/helpers/committee.go b/beacon-chain/core/helpers/committee.go
index a5d6d3a97d..fec80ad251 100644
--- a/beacon-chain/core/helpers/committee.go
+++ b/beacon-chain/core/helpers/committee.go
@@ -143,33 +143,6 @@ func ComputeCommittee(
 	return shuffledList[start:end], err
 }
 
-// AttestingIndices returns the attesting participants indices from the attestation data. The
-// committee is provided as an argument rather than a direct implementation from the spec definition.
-// Having the committee as an argument allows for re-use of beacon committees when possible.
-//
-// Spec pseudocode definition:
-//   def get_attesting_indices(state: BeaconState,
-//                          data: AttestationData,
-//                          bits: Bitlist[MAX_VALIDATORS_PER_COMMITTEE]) -> Set[ValidatorIndex]:
-//    """
-//    Return the set of attesting indices corresponding to ``data`` and ``bits``.
-//    """
-//    committee = get_beacon_committee(state, data.slot, data.index)
-//    return set(index for i, index in enumerate(committee) if bits[i])
-func AttestingIndices(bf bitfield.Bitfield, committee []uint64) ([]uint64, error) {
-	indices := make([]uint64, 0, len(committee))
-	indicesSet := make(map[uint64]bool, len(committee))
-	for i, idx := range committee {
-		if !indicesSet[idx] {
-			if bf.BitAt(uint64(i)) {
-				indices = append(indices, idx)
-			}
-		}
-		indicesSet[idx] = true
-	}
-	return indices, nil
-}
-
 // CommitteeAssignmentContainer represents a committee, index, and attester slot for a given epoch.
 type CommitteeAssignmentContainer struct {
 	Committee      []uint64
diff --git a/beacon-chain/core/helpers/committee_test.go b/beacon-chain/core/helpers/committee_test.go
index d7c687ee64..22c8d86133 100644
--- a/beacon-chain/core/helpers/committee_test.go
+++ b/beacon-chain/core/helpers/committee_test.go
@@ -85,101 +85,6 @@ func TestComputeCommittee_WithoutCache(t *testing.T) {
 	}
 }
 
-func TestAttestationParticipants_NoCommitteeCache(t *testing.T) {
-	committeeSize := uint64(16)
-	validators := make([]*ethpb.Validator, committeeSize*params.BeaconConfig().SlotsPerEpoch)
-	for i := 0; i < len(validators); i++ {
-		validators[i] = &ethpb.Validator{
-			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
-		}
-	}
-
-	state, err := beaconstate.InitializeFromProto(&pb.BeaconState{
-		Slot:        params.BeaconConfig().SlotsPerEpoch,
-		Validators:  validators,
-		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
-	})
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	attestationData := &ethpb.AttestationData{}
-
-	tests := []struct {
-		attestationSlot uint64
-		bitfield        bitfield.Bitlist
-		wanted          []uint64
-	}{
-		{
-			attestationSlot: 3,
-			bitfield:        bitfield.Bitlist{0x07},
-			wanted:          []uint64{344, 221},
-		},
-		{
-			attestationSlot: 2,
-			bitfield:        bitfield.Bitlist{0x05},
-			wanted:          []uint64{207},
-		},
-		{
-			attestationSlot: 11,
-			bitfield:        bitfield.Bitlist{0x07},
-			wanted:          []uint64{409, 213},
-		},
-	}
-
-	for _, tt := range tests {
-		attestationData.Target = &ethpb.Checkpoint{Epoch: 0}
-		attestationData.Slot = tt.attestationSlot
-
-		committee, err := BeaconCommitteeFromState(state, tt.attestationSlot, 0 /* committee index */)
-		if err != nil {
-			t.Error(err)
-		}
-		result, err := AttestingIndices(tt.bitfield, committee)
-		if err != nil {
-			t.Errorf("Failed to get attestation participants: %v", err)
-		}
-
-		if !reflect.DeepEqual(tt.wanted, result) {
-			t.Errorf(
-				"Result indices was an unexpected value. Wanted %d, got %d",
-				tt.wanted,
-				result,
-			)
-		}
-	}
-}
-
-func TestAttestationParticipants_EmptyBitfield(t *testing.T) {
-	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := 0; i < len(validators); i++ {
-		validators[i] = &ethpb.Validator{
-			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
-		}
-	}
-
-	state, err := beaconstate.InitializeFromProto(&pb.BeaconState{
-		Validators:  validators,
-		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
-	})
-	if err != nil {
-		t.Fatal(err)
-	}
-	attestationData := &ethpb.AttestationData{Target: &ethpb.Checkpoint{}}
-
-	committee, err := BeaconCommitteeFromState(state, attestationData.Slot, attestationData.CommitteeIndex)
-	if err != nil {
-		t.Fatal(err)
-	}
-	indices, err := AttestingIndices(bitfield.NewBitlist(128), committee)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if len(indices) != 0 {
-		t.Errorf("Attesting indices are non-zero despite an empty bitfield being provided; Size %d", len(indices))
-	}
-}
-
 func TestVerifyBitfieldLength_OK(t *testing.T) {
 	bf := bitfield.Bitlist{0xFF, 0x01}
 	committeeSize := uint64(8)