The Hull Daily Mail is challenging an injunction banning it from revealing details about an HIV health scare terrifying families in Hull and the East Riding.

Five hundred patients have received letters advising them that a health worker involved in their care was infected with the HIV virus, and they have been advised to arrange an HIV test.

However, because of the injunction, which was taken out against the Hull and East Yorkshire Hospitals NHS Trust, patients cannot be told when or how they were potentially put at risk.

Acting on behalf of the infected worker, the injunction was taken out by the Medical Defence Union at the High Court of Justice in London, and prevents the Trust – or any other party, including the Hull Daily Mail – from identifying the worker, or any details that could lead to their identification.

The injunction states the worker can only be known as “A” or a health care worker and bans details which could lead to their identity being revealed, including where “A” worked, how long “A” had worked for the Trust or which hospitals were involved.

The Hull Daily Mail has now decided to take legal action as a matter of public interest and has notified the Medical Defence Union, and lawyers acting for the hospital trust of its intention to challenge the injunction.

The paper does not intend to name the worker, irrespective of the outcome of the legal challenge.

Editor John Meehan said: “The injunction has the effect of exacerbating the anguish of patients involved in this alert.

“Not only are they deeply concerned about the risk of HIV infection, they have not been able to get answers to specific questions about the nature of the risk and when and how they were exposed to it.

“We believe our readers have a right to this information and that is why we are applying for the order to be varied so that information, which will help our readers understand the nature of the risk, can be published.”

The paper decided to take action after it was inundated with calls from patients who had received the warning letter.

But because of the injunction the paper cannot publish their comments because of the risks of identifying the worker.

Details of which hospitals are involved in the scare or which surgical procedures are involved, can also not be revealed.