Zeta-Jones will appear as a witness in the case of Dawnette Knight, an unemployed woman accused of 26 stalking offences against the actress.

A court in Los Angeles heard yesterday that Knight, 32, allegedly made the threats in letters to the Chicago star’s father-in-law, film legend Kirk Douglas.

Detective Teresa Garrett told Los Angeles Superior Court that an “obituary style” letter was sent to Kirk Douglas, father of Zeta-Jones’s husband Michael.

Zeta-Jones and Michael Douglas are expected to take the stand as a judge decides whether there is enough evidence to order Knight to stand trial.