A private investigator hired by the Mail on Sunday bugged Liz Hurley’s home and ex-boyfriend Hugh Grant’s car to unlawfully obtain information about the actress’s finances, travel plans and medicals during her pregnancy, the High Court has been told.

Details of Ms Hurley’s breach of privacy claim against Associated Newspapers Limited (ANL) were revealed by the release of documents on Monday outlining allegations made by a number of individuals suing the publisher.

Actress Sadie Frost also claims she suffered “invasions of her privacy” through phone hacking and the tapping of ex-husband Jude Law’s landline when he was discussing details of their divorce settlement.

ANL also allegedly worked with a private investigator who unlawfully found the identity and address of a man he believed was in a relationship with ex-Liberal Democrat MP Sir Simon Hughes, the former politician claims.

ANL says the allegations in the documents, supplied to journalists as part of a preliminary hearing in the cases, are “firmly denied” and the claims are being brought too late.

David Sherborne, representing Ms Hurley, said in the written submissions that she was left “shocked and mortified” by the alleged targeting of her.

He said a private investigator, acting on behalf of the Mail on Sunday, hacked their phones, tapped landlines, placed “a sticky window mini-microphone on the exterior of her home window” and bugged Mr Grant’s car to obtain “private communications with Mr Grant, her financial details, her travel arrangements and medicals during her pregnancy and birth of her son”.

“The prospect of strangers listening into her live telephone calls and bugging her private property was a particularly grotesque thought that she had never considered possible,” her barrister said.

“(Ms Hurley) was also particularly appalled by Associated’s targeting of her during her pregnancy and following the birth of her baby.

“It left her sickened to see the snatched close-up picture of her baby’s face published by Associated when he was four months old with the new understanding that this intrusion was the exploitation of unlawful acts, deliberately directed at her with that intention.

“She recalls the feeling of vulnerability she felt at this time in her life, and the sense that despite precautions taken, she was unable to protect her son, or indeed other loved ones around her who similarly fell to be targeted as a result of their association with her.

“It angers (her) now to know that she never had a chance against all the artillery of unlawful means and private investigators that Associated used against her and which, unknown to her, underlay the articles published about her. She now understands how very real the feeling of being trapped and surrounded on all sides by unknown enemies truly was.”

Ms Frost claims her private communications, financial details and travel plans were unlawfully obtained on behalf of the Mail on Sunday, Mr Sherborne said.

He added that she “finds it deeply upsetting that her reliance on a telephone, which she considered to be a lifeline during some of the most painful moments of her life such as her divorce, her mental health issues and the death of her father, was being used to create stories has left her deeply distressed”.

“To have it confirmed, and that this took place in relation to her circle of friends and family too, has made her feel extremely violated and angry since she wanted to protect her family as much as she could, especially given the situation which they were all facing.

“Associated’s acts left (her) feeling vulnerable and it exacerbated already difficult moments in her life. Yet Associated shamelessly exploited that pain by revealing it to readers in immense detail for its own profit.”

Mr Sherborne said Ms Frost was allegedly misled for years into believing someone close to her was responsible for revealing information.

Sir Simon is “deeply upset and shocked to learn that he was deliberately targeted by Associated”, Mr Sherborne also said.

He added that a private investigator hacked the ex-MP’s voicemail messages and “blagged” bank and phone records for information that was passed to the Mail on Sunday.

No story was published by the newspaper in the end, but it made a payment in relation to the alleged unlawful activity surrounding “Simon Hughes’ boyfriend”, Mr Sherborne said.

The barrister added: “Whilst (Sir Simon) recognises that being a politician means he has to accept press attention for his professional activities, he firmly believes that this is no justification at all for journalists, or others acting on their behalf, to intercept his private communications or to trade in unlawful or illegal information gathering of his personal information in order to find stories to publish about him.

“Associated’s unlawful acts were therefore both grossly intrusive and morally unacceptable.”