The wife of serial killer Harold Shipman is to be called to give evidence to the inquiry into her husband's crimes, it was revealed today.

Primrose Shipman has so far only given a general statement to the inquiry and has refused to speak publicly about the events.

But a special hearing of the inquiry, which is headed by Dame Janet Smith and which has power of subpoena, today ruled that Mrs Shipman, 54, should be called to testify in public at Manchester Town Hall on Friday.

The inquiry rejected an application on Mrs Shipman's behalf that she should be allowed to give evidence either behind closed doors or via a video link from another building.

Instead, the mother-of-four is due to attend Manchester Town Hall this Friday to answer questions in public about the circumstances surrounding the deaths of three of her husband's former patients.

The inquiry has already heard that Mrs Shipman may have been present at the death of one of Shipman's possible victims, 74-year-old Irene Chapman.

Today, lawyers representing Mrs Shipman asked Dame Janet to allow her to give evidence in private.

Her counsel, Jim Sturman, said: "She is uniquely terrified about being forced to attend. She fears the pressure she is under will be reflected in her evidence and the quality of her evidence."

And he added: "Within the context of this case, she is by far the most vulnerable witness." Counsel for the inquiry, Caroline Swift QC, argued it would be unfair on other vulnerable and nervous witnesses if Mrs Shipman was allowed to give evidence in private.