diff --git a/src/keeper/contracts/DIDRegistry.ts b/src/keeper/contracts/DIDRegistry.ts
index 026491d..5d98049 100644
--- a/src/keeper/contracts/DIDRegistry.ts
+++ b/src/keeper/contracts/DIDRegistry.ts
@@ -75,7 +75,10 @@ export default class DIDRegistry extends ContractBase {
     }
 
     public async revokePermission(did: string, grantee: string, ownerAddress: string) {
-        return this.send('revokePermission', ownerAddress, [zeroX(did), zeroX(grantee)])
+        return this.send('revokePermission', ownerAddress, [
+            didZeroX(did),
+            zeroX(grantee)
+        ])
     }
 
     public async getPermission(did: string, grantee: string): Promise<boolean> {
diff --git a/src/ocean/OceanAssets.ts b/src/ocean/OceanAssets.ts
index b171ca0..2515855 100644
--- a/src/ocean/OceanAssets.ts
+++ b/src/ocean/OceanAssets.ts
@@ -5,7 +5,7 @@ import { MetaData } from '../ddo/MetaData'
 import { Service, ServiceAccess } from '../ddo/Service'
 import Account from './Account'
 import DID from './DID'
-import { fillConditionsWithDDO, SubscribablePromise } from '../utils'
+import { fillConditionsWithDDO, SubscribablePromise, didZeroX } from '../utils'
 import { Instantiable, InstantiableConfig } from '../Instantiable.abstract'
 import { OrderProgressStep } from './utils/ServiceUtils'
 
@@ -416,4 +416,67 @@ export class OceanAssets extends Instantiable {
             }
         }
     }
+
+    /**
+     * Get FreeWhiteList for a DID
+     * @param  {string} did Asset DID.
+     * @return {Promise<string[]>} List of addresses.
+     */
+    public async getFreeWhiteList(did: string): Promise<string[]> {
+        const events = await this.ocean.keeper.didRegistry.getPastEvents(
+            'DIDPermissionGranted',
+            {
+                _did: didZeroX(did)
+            }
+        )
+        const list = events.map(({ returnValues }) => returnValues._grantee)
+        const filteredList = []
+        for (let index = 0; index < list.length; index++) {
+            const address = list[index]
+            const hasPermission = await this.ocean.keeper.didRegistry.getPermission(
+                did,
+                address
+            )
+            if (hasPermission) filteredList.push(address)
+        }
+        return filteredList
+    }
+
+    /**
+     * Add consumer to FreeWhiteList for a DID
+     * @param  {string} did Asset DID.
+     * @param  {string} consumer Ethereum address to add to the list.
+     * @param  {Account} account Ethereum account of DID owner
+     * @return None
+     */
+    public async addConsumerToFreeWhiteList(
+        did: string,
+        consumer: string,
+        account: Account
+    ): Promise<TransactionReceipt> {
+        await this.ocean.keeper.didRegistry.grantPermission(
+            did,
+            consumer,
+            account.getId()
+        )
+    }
+
+    /**
+     * Remove consumer from DID's FreeWhiteList
+     * @param  {string} did Asset DID.
+     * @param  {string} consumer Ethereum address to add to the list.
+     * @param  {Account} account Ethereum account of DID owner
+     * @return None
+     */
+    public async removeConsumerFromFreeWhiteList(
+        did: string,
+        consumer: string,
+        account: Account
+    ): Promise<TransactionReceipt> {
+        await this.ocean.keeper.didRegistry.revokePermission(
+            did,
+            consumer,
+            account.getId()
+        )
+    }
 }
diff --git a/test/integration/ocean/AssetOwners.test.ts b/test/integration/ocean/AssetOwners.test.ts
index 33297cb..215c197 100644
--- a/test/integration/ocean/AssetOwners.test.ts
+++ b/test/integration/ocean/AssetOwners.test.ts
@@ -8,6 +8,8 @@ describe('Asset Owners', () => {
 
     let account1: Account
     let account2: Account
+    let consumer1: Account
+    let consumer2: Account
 
     let metadata = getMetadata()
 
@@ -16,6 +18,8 @@ describe('Asset Owners', () => {
 
         // Accounts
         ;[account1, account2] = await ocean.accounts.list()
+        consumer1 = (await ocean.accounts.list())[3]
+        consumer2 = (await ocean.accounts.list())[4]
 
         if (!ocean.keeper.dispenser) {
             metadata = getMetadata(0)
@@ -113,4 +117,21 @@ describe('Asset Owners', () => {
 
         assert.equal(newOwner, account2.getId())
     })
+
+    it('should add and remove correctly an address to/from FreeWhiteList on an asset', async () => {
+        const ddo = await ocean.assets.create(metadata as any, account1)
+        await ocean.assets.addConsumerToFreeWhiteList(ddo.id, consumer1.getId(), account1)
+        await ocean.assets.addConsumerToFreeWhiteList(ddo.id, consumer2.getId(), account1)
+        const list = await ocean.assets.getFreeWhiteList(ddo.id)
+        assert.notEqual(-1, list.indexOf(consumer1.getId()))
+        assert.notEqual(-1, list.indexOf(consumer2.getId()))
+        await ocean.assets.removeConsumerFromFreeWhiteList(
+            ddo.id,
+            consumer1.getId(),
+            account1
+        )
+        const remList = await ocean.assets.getFreeWhiteList(ddo.id)
+        assert.equal(-1, remList.indexOf(consumer1.getId()))
+        assert.notEqual(-1, remList.indexOf(consumer2.getId()))
+    })
 })