A fatal accident inquiry will be held into the Clutha tragedy but there is "insufficient evidence" for criminal proceedings, prosecutors have said.

Ten people died when a police helicopter crashed on to the roof of the Clutha Vaults bar in Glasgow in November 2013.

More than 100 people were enjoying a night out at the pub when the police helicopter, returning to its base on the banks of the River Clyde, crashed through the roof on November 29 2013.

The Crown Office and Procurator Fiscal Service said in a statement: "The investigation into the Clutha helicopter crash has reached a significant stage and Crown Counsel, the most senior lawyers in Crown Office, have formally instructed a fatal accident inquiry be held.

"Following submission of a detailed report by the helicopter team, Crown counsel have also concluded that there is insufficient evidence available to justify instructing criminal proceedings."

Seven customers - John McGarrigle, Mark O'Prey, Gary Arthur, Colin Gibson, Robert Jenkins, Samuel McGhee and Joe Cusker- died.

Helicopter pilot David Traill and crewmates Tony Collins and Kirsty Nelis also died.

An Air Accidents Investigation Branch report published in 2015 found two fuel supply switches were off and the pilot did not follow emergency procedures after a fuel warning in the cockpit.

Norman Maciver, who was the last survivor to be released from hospital, told STV News: "I wasn't aware that it was a secret or just announced.

"I am more concerned about the time it has taken, four years down the line and still no answers for the families who lost loved ones."

Andrew Henderson, a partner with Thompsons solicitors, which represents many injury victims and families of those who died, said the length of wait for an inquiry was "unacceptable".

He said: "While it will be welcome news for our clients that there is now some movement by the Crown Office on beginning the FAI process, it's highly regrettable it has taken so long.

"The whole purpose of FAIs is to make recommendations that will stop similar tragedies happening in the future and therefore the process moving forward in a timely fashion is crucial. "The fact that the inquiry is likely to begin almost five years after this awful accident is not acceptable.

"This again highlights what my law firm has long argued, which is that the whole FAI system in Scotland needs to be overhauled so that inquires are held more quickly and that bereaved families are at the very heart of the process. I still believe that this is not the case."

Earlier this month, damages were awarded to people injured in the crash and family members of those who died.

A total of £1.3m was paid by the owners of the helicopter firm to ten people injured, while cases brought by 16 others affected were settled for undisclosed amounts.

Compensation claims were made by Babcock for post-traumatic stress, serious brain or spinal injuries.