Miss Allan is seeking libel damages over a television programme which she says suggested she had an affair with Eugene Terre-Blanche, leader of South Africa's neo-Nazi AWB party.
George Carman QC, for Channel 4 - which says she did have the adulterous relationship - asked Miss Allan why if, as she said, she had only ever had sexual intercourse with her husband, whom she divorced in 1984, X-rays taken in 1989 showed the device inside her.
Miss Allan, who has told the High Court she had psychiatric treatment for her lack of interest in sex, said it was fitted when she was married and was still there.
Mr Carman asked about a love letter sent to her in July 1984 by Captain Ricardo - a married Italian airline pilot alleged by Mr Carman to have had a sexual affair with Miss Allan while she was still married, as described by her in a sexually graphic notebook. Miss Allan has said the notebook entries were 'fantasy'.
She agreed that the letter from Ricardo, which said: 'I love you forever . . . you are the best thing in all my life' and was signed 'All my love, your Ricardo', was real.
Miss Allan, 41, admitted she was infatuated with Ricardo, who she did not at first realise was married. There was a degree of sexual foreplay between them, but she had not gone the 'whole way'.
Miss Allan, who now lives at Hampton Court, Surrey, is suing over the film The Leader, His Driver and the Driver's Wife, which she claims portrayed her as a 'lady of easy virtue'.
Mr Carman asked if Miss Allan had told a former flatmate, Linda Shaw, that Mr Terre-Blanche was 'a great lay but a little heavy'. She replied: 'That is totally untrue.' She also denied that she would sit at Mr Terre-Blanche's feet when he came round to her flat and 'ply' him with Chivas Regal whisky - his favourite drink. She denied she would make a meal for him of 'Boerewors' sausage and that they would laugh together over graffiti which had appeared in Johannesburg proclaiming 'Jani Allan loves Boerewors' - a crude reference to the male sexual organ. She said the graffiti had caused her great upset.
It is not clear how Miss Allan's explicit personal notebook, which galvanised the hearing, came into Channel 4's possession on the second day of the action.
Miss Allan said yesterday that the notebook, which covers the years 1984-85, was 'absolutely, categorically not' written for public consumption.
She did not give permission to anyone to give it to Channel 4 and had never been told how they got hold of it.
She knew the notebook had been stolen but not by whom.
Mr Carman said the court should know the notebook arrived in a parcel, via a court usher. It carried his name and was addressed to the courtroom.
'It was delivered by one of those bikes which go around London,' he told the judge. 'We don't know who (it was sent) by.'
The hearing was adjourned until Monday.Reuse content