ITV shows went off air as police evacuated the television studios and two nearby Tube stations in west London following reports of a “suspicious item” addressed to Lorraine Kelly.
Viewers were left baffled when This Morning went off air suddenly, to be replaced by a recorded compilation show.
And a recorded episode of Loose Women replaced the live version.
A police cordon was put around the studios, with officers preventing staff from accessing the building.
The Metropolitan Police said they were called shortly after 11am on Thursday when a suspicious package was found at Wood Lane in White City.
“The area was evacuated as a precaution and White City and Wood Lane tube stations were temporarily closed,” the force said in a statement.
“The incident was stood down shortly before 12.49hrs. An investigation is ongoing.”
They later said the item had been classed as “non-suspicious”.
An ITV source told The Sun Kelly was “very concerned” about being a potential target.
"Word quickly got around that whatever the box contained, it was addressed to Lorraine,” they said. ““Everyone at ITV loves her - so people were upset and very concerned over the whole incident.”
This Morning was forced to issue an apology for the break in live programming.
A statement said: “We are currently running pre-recorded content and hope to be back with you soon.”
A spokesperson for ITV said: “Due to a suspected security alert, the building which ITV daytime broadcast from was safely evacuated.
“The issue has been resolved and staff have returned to the building following the all-clear from the police. We apologise for the interruption to the schedule and we have now returned to normal programming.”
The ITV Lunchtime News, which is produced by ITN in central London, was aired live and without interruption.
ITV announced it was moving to the former BBC Television Centre last summer. The channel said it had agreed terms to take a 13-year lease on the building from the BBC, bringing all of its London staff into one location for the first time.
The studios are used to film a range of shows including This Morning, Loose Women, The Graham Norton Show and Later... With Jools Holland.