The long wait for answers demanded by the families of those who died in the Clutha helicopter crash may soon be over but the calls for justice are likely to continue.

First Minister Nicola Sturgeon has twice raised concerns with the UK Government about the delay in publication of the Air Accidents Investigation Branch (AAIB) report into the disaster, now nearly two years ago on November 29 2013.

Shortly after the first anniversary of the crash, Ms Sturgeon wrote to Prime Minister David Cameron urging him to do all he can to expedite the investigation by the reserved UK agency so that her own devolved agencies can assess whether health and safety reforms and perhaps criminal charges should follow.

On December 3 2014, she wrote: "Practically speaking, the Procurator Fiscal is unable to move on their investigations into this matter until the AAIB publishes its final report in mid 2015.

"That risks delay in any decision about criminal proceedings and the holding of a fatal accident inquiry which I am sure you will agree is an unsatisfactory position."

She added: "I share the Solicitor General's concern and would ask you to do all you can to ensure AAIB progress their investigation as quickly as possible and that they ensure a smooth flow of information between the AAIB and the Procurator Fiscal."

The AAIB said the report would be published in the middle of 2015, but by the end of July Ms Sturgeon was becoming increasingly impatient.

The pub re-opened with a huge mural depicting the famous faces that had enjoyed a drink in the pub, from Billy Connolly to Frank Zappa, celebrating the good times, but the tragedy and the lack of answers was still an open sore.

At the opening, Ms Sturgeon said: "We're all very aware of the fact that the families who lost loved ones in here that night are still waiting for answers on what went wrong.

"I very much hope that in the not too distant future that they will have those answers, and that that investigation is now entering its final stages.

"Hopefully before too long the families will have the answers that they are looking for and the answers that they deserve."

More than a month later, on August 29, she wrote to UK Transport Minister Patrick McLoughlin for an update.

"While I fully understand the need for the most rigorous possible investigation, taking account of all possible factors, I am concerned at this apparent slippage in timescale," she said.

"The Clutha families have already waited for almost two years and I believe they should have an assurance that the report is now nearing completion and will be published imminently, and certainly before the second anniversary of the tragedy.

"I would be grateful if you could give urgent consideration to this matter and take any necessary steps to expedite the publication of the final AAIB report."

The AAIB said the report would only be published once it is "satisfied all evidence and any additional information has been fully considered".