Detainees at UK immigration centres are being hospitalised at the rate of almost one a day, according to new figures that raise fresh concerns over the safety of vulnerable people held inside.

Home Office data, obtained following a freedom of information request, revealed that in 2017, there were 330 visits to hospital by detainees held in immigration removal centres.

The figures were recorded between January and December 2017, shortly after the Home Office introduced its “adults at risk policy”, which was meant to keep vulnerable people out of detention.

The findings follow a scathing report last month by the home affairs select committee that said the Home Office had overseen serious failings in almost every aspect of the immigration detention process.

Sonya Sceats, chief executive of charity Freedom from Torture, which submitted the FoI request, said: “The Home Office figures make it abundantly clear that there are very ill and vulnerable people in these immigration detention centres.

“It is shocking to think that almost every day of the month, there is a hospital admission. From removal centre reports to accounts from torture survivors in treatment with us, we know that self-harm, overdoses and poor provision of medication are commonplace.”

Sceats outlined one case involving a distressed detainee who made 22 calls on the emergency bell in his cell before staff came to see him and called an ambulance.

“Torture survivors and vulnerable people should never be detained for immigration purposes,” she added.

Another parliamentary report published in February, this time by the joint committee on human rights (JCHR), called for an end to indefinite detention in immigration centres, and said people should ideally be held for no longer than 28 days.

A Home Office spokesperson said: “The health and welfare of those in immigration detention is of the utmost importance. All immigration detention centres have trained medical staff on hand to provide care to those in detention.”