Officers from the British Transport Police (BTP) are urgently seeking assistance from the public in trying to trace a female.
They believe the woman may be able to assist with enquiries after a guide dog was attacked by two other dogs at Glasgow Central station on Friday, October 2, 2015 around 4.25pm.
The two dogs have been described as a tan coloured Staffordshire or Pitbull Terrier and a German Shepherd.
The woman shown in the CCTV image is described as having long brown hair. She was wearing glasses and a grey hooded top with the number 88 on the front.
It is believed she may have later boarded the 5.30pm service to London Euston.
Constable Colin Campbell, the officer in charge of the enquiry, is appealing to anyone who recognises the woman shown in the photograph to contact them.
Anyone with information should contact British Transport Police on 0800 40 50 40 or by texting 61016 quoting reference B1 of 17/02/2016.
Information can also be given anonymously to the independent charity Crimestoppers on 0800 555 111.