Virgin Media has advised its 800,000 customers to change their passwords as a matter of priority to protect against hackers.

An investigation by Which? found that hackers could access the provider's Super Hub 2 router, allowing access to users' smart devices.

The investigation found that a child's toy and domestic CCTV cameras were among the vulnerable devices.

Virgin Media said the risk was small but advised any customers using default network and router passwords to change them immediately.