The family of Mary Bastholm has issued a statement as investigation work continues at the Clean Plate Cafe in Gloucester today.
The Constabulary is stressing that the current work relates to assessments of the site, which are likely to take a number of days, and that excavation work has not begun.
Officers say that they could be at the site for a number of weeks.
Mary's family said: “We are aware of the ongoing developments around Mary’s disappearance and are being kept up to date and supported by Gloucestershire Police Family Liaison Officers, at this time please may we ask for privacy so we can grieve for Mary and direct any media queries to Gloucestershire Police’s Press Office.”
Mary was 15 years old when she was reported missing on 6 January 1968 and she has never been found.
Mary’s disappearance had previously been linked to serial killer Fred West and there was suspicion he was involved in her death.