The Home Office faces a wave of legal claims after the UK’s surveillance watchdog found a blanket policy of seizing thousands of asylum seekers’ mobile phones caused “significant harm”. The Investigatory Powers Commissioner’s Office has written to a large group of asylum seekers to notify them of their right to bring a case before a specialist surveillance tribunal. In a notice published this week, the IPCO said its investigation into the phone seizures, which occurred during 2020, found immigration officials made serious errors in complying with investigatory powers rules. The organisation, which oversees public authorities’ use of intrusive surveillance powers, found that “significant harm and prejudice was suffered because of [immigration] officers’ actions”. It said: “It is in the public interest that affected persons are informed of the error.” Last year, the high court ruled that the Home Office unlawfully operated the blanket policy under which immigration officials seized the phones of all asylum seekers arriving in the UK on small boats. The court found officials did not have parliamentary authority to extract data from phones and retain devices, which meant affected people were unable to contact family members or access documentation. The case revealed how immigration enforcement officers had unlawfully required asylum seekers to disclose the pins of their phones under threat of prosecution. A Whitehall source said the Home Office referred itself to the IPCO, which conducted its own investigation into the seizures. The IPCO, which is headed by the senior judge Sir Brian Leveson, has written to people affected by the policy but said it does not have contact details for everyone involved. It said potential claimants should take note of information it is providing about applying to the investigatory powers tribunal (IPT). Lucie Audibert, a lawyer at Privacy International, said the outcome of the IPCO’s investigation was significant because it could open a new avenue for compensation. She said it was “a really big step to provide redress to people who were affected” – potentially numbering in the thousands. Clare Jennings, a solicitor at Gold Jennings who worked on the high court case, said: “We welcome the commissioner’s conclusion that the Home Office made serious errors in the use of their investigatory powers.” She said lawyers were considering the implications of the IPCO notice, but “anyone whose phones were taken under the policy are likely to be eligible to claim compensation and it would be advisable that they seek legal advice”. Another lawyer familiar with the case said that while potentially thousands were affected by the seizure policy, the tribunal may be more appropriate in cases where the officials had not just seized phones but also used intrusive measures against them. The IPT is a specialist judicial body that investigates complaints against the intelligence services and public authorities that use investigatory powers. It can consider secret evidence and make remedial orders including compensation awards. A spokesperson for the Home Office said it would “continue to cooperate with the Investigatory Powers Commissioner’s Office on this matter and will respond to any claims made in the investigatory powers tribunal accordingly”.