Holly Willoughby under police guard after learning of plot to kidnap her

Holly Willoughby is reportedly under police guard following a suspected plot to kidnap her.

Reports, via The Sun, suggested the 42-year-old was pulled from Thursday's This Morning show at the last minute after being told of the threat and has been given protection by police.

The ITV presenter is said to be "distraught" and is being monitored round-the-clock police guard the home she shares with husband, Daniel Baldwin, their sons Harry and Chester, and daughter Belle.

Essex police said a 36-year-old man was arrested at a flat in Harlow on Wednesday night on suspicion of conspiracy to kidnap. The man remains in custody as police continue their inquiries.

According to reports, police alerted ITV producers just moments before Holly was due to go on air.

Police officers are also outside Holly's home where she lives with her husband Daniel Baldwin and their sons Harry and Chester and daughter Belle.

ITV are also providing security and support for Holly, the PA news agency understands.

The Sun reports that police found "sinister messages" allegedly threatening to "seriously harm" the mum-of-three.

The outlet reports the person is not known to the star.

Another source told the publication that police are treating "this as a credible conspiracy to kidnap Holly".

"There were apparently some sinister and threatening messages found on electronic devices threatening to seriously harm her."

ITV brought in Alison Hammond to stand in for Holly as she joined Josie Gibson last-minute.

Senior staff have been looking for a permanent presenter to work alongside Holly after Phillip Schofield's exit earlier this year.