Private contractor Capita said it has no record of sending an anti-racism campaigner a text urging him to contact them about his immigration status.
Suresh Grover, founder of The Monitoring Group, told The Independent he was "absolutely shocked and quite horrified" to receive the text message warning him he "may not have leave to remain in the UK."
A spokesperson for Capita, who sent the messages at the request of the Home Office, said of the 58,800 people they contacted by text or email between December 2012 and June 2013, just 14 complaints were received claiming they had been sent in error.
"Most complaints occurred in the earlier part of this period where Capita was, as part of the contract, updating sometimes out-of-date Home Office records," the spokesperson added.
More top news
More than 50 dog surfers of all breeds and sizes joined an annual dog surfing competition in California
A painting by artist LS Lowry is to go on show to the public for the first time.
A third of Olympic and world championships medals have been won by athletes with allegedly suspicious doping test results, report claims