Gardaí will resume searching marshland in Dundalk this morning as they investigate the disappearance of Ciara Breen.
She went missing almost 20 years ago in February 1997, when she was 17, and has not been seen since.
Yesterday officers began a fresh search in an area known as Balmer's Bog.
A man in his 50s was arrested in relation to the case last April, but released without charge.
Gardaí received two anonymous letters following local and national appeals for information, and they say this new search is just one line of inquiry.