Celtic FC will break their silence over historic sex abuse allegations in the next 24-hours by dramatically revealing that they have been conducting a top-level inquiry for the past two years.

The Herald and Evening Times can reveal the probe – which is ongoing – has been headed by senior officials, legal counsel and third parties in complete secrecy as it looks to trawl through years of allegations to reach the truth.

Because of the sensitivity around the claims including potentially both legal and civil actions, only a handful of people have been privy to the operation.

However after a new storm began to rage following the intervention of SNP MSP James Dornan and Tory Adam Tomkins, the club is preparing to go public on the work that has been done thus far to investigate what unfolded.

Read more: Celtic chief Peter Lawwell slammed by MSP James Dornan over Boys Club victims

Peter Lawwell, Celtic’s chief executive, has written to both the politicians in response to criticisms they levelled at him and his club.

It is understood they will be left in no doubt that the Glasgow club has been working around the clock on the issue and liaising with authorities.

However with the activity still ongoing, they will be at pains to ensure nothing detracts from the work going on.

One source said: “Celtic have had no option but to play this close to their chest, not only because of the individual sensitivities, but owing to the legal considerations involved.

“An inquiry has been ongoing now for two years and continues to progress.”

Celtic came under renewed criticism when Jim McCafferty became the fourth person connected with Celtic Boys’ Club or the club itself to be jailed over abuse.

He was caged for six years, following Jim Torbett, Frank Cairney and Gerald King through the justice system.

Read more: Ex-Celtic youth coach Jim McCafferty admits sex abuse against young boys

McCafferty admitted preying on 10 teenage boys between 1972 and 1996.

Celtic Boys Club founder Jim Torbett was jailed for a second time last November over abusing boys.

Coach Frank Cairney, 83, and ex chairman Gerald King, 66, have also been convicted in recent months.

A statement from Celtic after McCafferty's sentencing expressed "regret and sorrow" to those affected by the actions of the paedophile and offered "sincere sympathy".

But critics said that didn’t go far enough.

Mr Dornan and Professor Tomkins both shared letters they sent to the club in the wake of former coach Jim McCafferty being jailed for more than six years.

Mr Dornan, MSP for Glasgow Cathcart, told yesterday how he sent a letter to the club's chief executive Peter Lawwell on May 16

The Celtic fan said it was "with great sadness" he felt "compelled" to write the letter, in which he said it was "in no way accurate" to say the relationship between Celtic FC and Celtic Boys Club was as separate entities.

He wrote: "Boys were sold the idea of playing for the Boys Club as having a foot into Celtic FC, this from Celtic scouts.

"The relationship between the coaches, including Messrs (Jim) Torbett and (Frank) Cairney and high-ranking Celtic officials, was clear for all to see.

"Every Celtic Boys Club annual event was full of Celtic players and officials, generally giving out the prizes to the lucky young players who saw themselves as close to signing or had already signed for the club."

Read more: Celtic Boys Club kitman Jim McCafferty abuse victims' compensation call

He added: "I accept that there may be some legal distance between the two but given what I and many others have seen Celtic have without doubt a moral responsibility to compensate for what happened under their watching eye.

"I urge you to take on this responsibility, not blame, apologise for what happened to these deeply damaged young men, accept you can't undo what has been done and offer compensation for those who were treated in such a terrible way by people using, and abusing, the proud name of Celtic FC.

"After seeing the latest in a far too long line of Celtic Boys Club coaches being found guilty of the foulest abuses you continue to abrogate your responsibilities as you have to date on this issue then, in my view, you bring nothing but shame to the reputation of Celtic and the wider Celtic family."

Mr Tomkins also called for a compensation package to be set up, citing Manchester City FC as an example.

In his letter, the Scottish Conservative MSP said: "Through a series of criminal trials we now know something of the scale of the abuse committed by a number of the men associated with Celtic boys' club.

Read more: Celtic accused of 'insulting' survivors of paedophile Jim McCafferty

"These are no longer allegations - in the cases in question they have been proved in a court of law.

"What we do not know is what Celtic FC knew about these offences and when they knew it.

"These questions must now be independently and fully investigated and, if necessary, a compensation scheme should be established such as that set up earlier this year by Manchester City FC.

"Several constituents have contacted me in recent weeks about these matters, and their concerns must be addressed."

Mr Lawwell has now written a robust response to both of their correspondences.

Read more of today's top Glasgow stories

They are expected to include details of the inquiry.