Police failings in the search for a pensioner found dead eight days after she went missing have been highlighted in a watchdog's report.

Janet McKay, 88, suffered from dementia and a series of other health problems, which led to police classifying her as being at "high risk" when she disappeared from her home in Glasgow's Knightswood on September 16, 2015.

However, "procedural and investigative shortcomings" were highlighted in a report into the conduct of the inquiry by the Police Investigations and Review Commissioner (Pirc).

These included failures to "act upon a number of vital investigative leads" and to "follow effective briefing and debriefing processes that would keep officers informed of new information and developments during the inquiry".

The family of Mrs McKay has welcomed a series of recommendations in the report, which include setting up major incident rooms for high-risk missing persons and properly recording, prioritising and reviewing evidence in such inquiries.

Police Scotland has apologised and said it fully accepted the watchdog's findings, issued on Friday.

Commissioner Kate Frame said Police Scotland had held "relevant information" about Mrs McKay on their vulnerable persons database, but took "several days" before supervisors were notified.

Details that were initially overlooked included the fact that Mrs McKay had used buses when she had gone missing before and had been found earlier that year "in a confused stated on a bus bound for Clydebank".

When the search for her was initially launched, police thought the advanced dementia sufferer may have been trying to locate her childhood home in Glasgow city centre.

Mrs McKay's body was discovered on September 24, 2015, at Rothesay Dock in Clydebank.

Ms Frame said: "This investigation highlighted a number of investigative and procedural shortcomings by Police Scotland in conducting a missing person inquiry for a vulnerable elderly woman who suffered from dementia.

"I have made a number of recommendations which I have already shared with the chief constable in light of this case, to enable him to put measures in place and take corrective action to prevent such failings in the future."

In a statement, Mrs McKay's family said: "We are aware of the findings of the Pirc report and are pleased to note that a number of recommendations have been made.

"We hope that going forward Police Scotland will look carefully at these recommendations and that valuable lessons have been learned.

"This has been a difficult time for our family. Janet was a loving mother and grandmother and we are thankful for the support we have received, but would ask for our privacy to be respected to allow us to come to terms with her loss in peace."

Assistant chief constable Mark Williams said: "I apologise on behalf of Police Scotland and once again offer my heartfelt condolences to the family and friends of Mrs Janet McKay.

"I fully accept the findings from the review by the Police Investigations and Review Commissioner and Police Scotland will continue to work with them to ensure all the lessons identified are addressed and built into our missing person investigations."