Sophie Smith, 21, was last being seen walking into the sea on Boxing Day.

Detectives investigating her disappearance have now confirmed she had left a note saying she wanted to kill herself.

Sophie, a biomedicine student at the University of East Anglia, had been spending Christmas with her family.

She suffered from severe anxiety and depression for which she was receiving treatment.

Mum Lynn Shaw, 56, realised Sophie had gone when she heard a door slam in the early hours and found her missing.

Police recovered CCTV footage from 3am on Boxing Day that appeared to show Sophie running towards the sea around 200 yards from her family home.

Inspector Will Drummond said: "We know from speaking to her family that Sophie had previously spoken about her intention to enter the sea to take her own life.

"Sadly, we can also confirm that Sophie had left a note and messages for loved ones, outlining her intentions."

Organisers of the Find Sophie Smith Facebook group, which now has nearly 30,500 members, said searches continued on Tuesday along the coast including at Breydon Water, Norfolk.

HM Coastguard says it has scoured 34 miles of coastline.

Sophie lived with her family in Gorleston, Norfolk, and her mum Lynn said: "Sophie's step-father Kevin and I would like to thank the public and police for their continued support and dedication in searching for Sophie.

"In our hearts we hold every hope she will return safe and well. However, as a family, knowing the troubles she was experiencing, we do fear the worst for our little girl.

"Sophie had openly discussed how she was struggling and was receiving treatment. I would urge anyone suffering anxiety or depression not to fight that battle alone and seek help."