A man has been arrested on suspicion of murder as police continue to look into the disappearance of author Helen Bailey.
The 51-year-old children's novelist has been missing for three months.
She was last seen on April 11, several weeks after the fifth anniversary of the death of her husband, John Sinfield, who drowned after being caught in a rip tide in Barbados during the couple's holiday in February 2011.
A 55-year-old man from Royston was arrested on Monday morning and is being questioned on suspicion of murder, disposing of a body in a manner likely to obstruct the coroner and suspicion of theft of money belonging Mrs Bailey, Hertfordshire Police said.
The force said: "Significant inquiries and searches have already been made as part of the investigation to trace Helen and further searches at her home address in Royston and an address in Broadstairs in Kent are taking place today."
The last sighting of Mrs Bailey, who wrote the Electra Brown novels, was at about 2.45pm on Monday April 11 near her home in Royston, where she was seen walking her dog.
In April, extensive searches were carried out at Mrs Bailey's holiday home in Broadstairs, Kent, where friends originally said they believed the author might have gone in order to have ''some time to herself''.