A 36-year-old man is being questioned by detectives about an alleged plot to kidnap Holly Willoughby.
The This Morning presenter, 42, pulled out of the ITV show on Thursday and her London home is reportedly being guarded by police.
Essex Police said the suspect was arrested on Wednesday on suspicion of conspiracy to kidnap and is in custody.
The force said in a statement: “A 36-year-old man from Harlow has been arrested on suspicion of conspiracy to kidnap as part of an ongoing investigation.
“The arrest was made on Wednesday October 4. He is currently in custody.”
The suspect is not known to the star, The Sun newspaper reported.
This Morning bosses were alerted to the alleged plot on Thursday morning and the presenter decided to pull out shortly before she was due to go on air, the newspaper added.
ITV are also providing round-the-clock security and support for Willoughby alongside the police, the PA news agency understands.