A High Court judge will decide today whether Oxfordshire hospital authorities should pay the £200,000 costs of transferring a female killer from Broadmoor Hospital to a less secure unit.

The 23-year-old, named only as 'T', was sent to the high security institution in April 1992 under the Mental Health Act following her manslaughter conviction on grounds of diminished responsibility.

Although she has a psychopathic disorder, doctors at Broadmoor say there is no longer any clinical or safety reason for keeping her there.

The woman was offered a transfer to a medium secure unit in Manchester early last year, but Oxfordshire Mental Healthcare NHS Trust and Oxfordshire NHS Health Authority have both refused to fund the cost of transferring her.

Trusts say her placement at the medium secure unit would cost up to £200,000 over a two-year period.

Apart from budgetary considerations, they claim that "high quality medium secure care can be provided locally in Oxfordshire when the patient becomes well enough for transfer".

Their case is being challenged at London's High Court by top civil rights QC, Richard Gordon, on behalf of 'T'.

He argued that the trust's stance conflicted with the clinical evidence and Government guidance that mental patients should be detained "in the least restrictive environment consistent with the need to protect them and the public".

After a day of legal argument on Friday, Mr Justice Sullivan said that he recognised the importance of the case and therefore needed time to consider his ruling.