A question mark remains over the whereabouts of missing author Helen Bailey after extensive police investigations failed to reap clues about her disappearance.

Royston Crow: Boris has also been missing since last Monday.Boris has also been missing since last Monday. (Image: Archant)

Police searched her home and the garden cesspit was drained, which ‘did not yield any clues’, a spokeswoman said.

Officers also examined her emails and social media, but don’t believe she has accessed either since she was last seen.

The police spokeswoman refused to comment on whether a third party is believed to be involved, saying: “At this stage we are still keeping an open mind on what may have happened to her so we cannot speculate on anything.”

The 51-year-old was reported missing to police on Friday, April 15, after having been last seen four days earlier with her miniature Dachshund Boris.

Royston Crow: Helen with her miniature dachshund Boris.Helen with her miniature dachshund Boris. (Image: Archant)

North Herts Chief Insp Julie Wheatley said: “We do not know if Helen and Boris are still together so we are asking anyone who thinks they may have come across him to please contact police.”

Specialist searches were carried out around Weston after a truck driver reported seeing someone matching her description – but without a dog – the day after she went missing.

A Facebook group and Twitter page named ‘Where is Helen Bailey?’ were both set up in the wake of her disappearance.

Anyone with information is asked to call 101 immediately.