It is less than three weeks since ex-Crewe defender Andy Woodward waived his right to anonymity to say that he was a victim of sexual abuse as a young footballer.

Since then, more than 20 former footballers - including ex-youth players, trainees and professionals - have also come forward with allegations of historical abuse in football.

The Football Association has announced an internal review; 350 people have alleged they are victims and 55 amateur and professional football clubs are linked to allegations of abuse.

FA chairman Greg Clarke says it is the biggest crisis he can remember for the organisation.

How did the news emerge?

On 16 November, former Bury and Sheffield United player Woodward, 43, waived his right to anonymity and told the Guardian that he was sexually abused as a youth player.

Since he spoke out, several others - including former England and Tottenham footballer Paul Stewart and ex-Manchester City striker David White - have told their stories publically.

On Monday, former Crewe Alexandra players Woodward and Steve Walters and ex-Manchester City youth player Chris Unsworth launched an independent trust that will "fight for justice" and support victims.

The Offside Trust is asking for donations from the English Football League, Football Association, Premier League, Professional Footballers' Association and commercial organisations that profit from the game.

How many clubs are involved?

To date, there are 55 amateur and professional football clubs linked to allegations of abuse, with several having confirmed their own inquiries.

Chelsea have apologised "profusely" to former footballer Gary Johnson over abuse he suffered in the 1970s and are conducting their own review into the case.

Charlton Athletic, Crewe Alexandra and Manchester City have also opened investigations into allegations of historical abuse.

Southampton are "fully supporting" Hampshire Police in its investigations and Newcastle say they will "co-operate fully" with the "relevant authorities".

Martin Glenn, FA chief executive has said: "We have clear rules in the game and if there's any evidence of a breach of those - and hushing up would be one - when it's our turn to apply the rules, we absolutely will, regardless of size of club."

He later added: "I can't say if there has been a cover-up in the game but I doubt it."

What is the FA doing?

The FA has begun an internal review - led by Kate Gallafent QC - to look at what officials and clubs knew and when.

The review will look at what information the FA was aware of at relevant times and what action was, or should have been, taken.

The FA has said it is working closely with police but added it "must ensure we do not do anything to interfere with or jeopardise the criminal process".

The Child Protection in Sport Unit, which has assisted the FA in relation to its safeguarding procedures since 2000, will also carry out an independent audit into the FA's practises.

BBC's Victoria Derbyshire programme reported that the FA scrapped a major review of its child protection policies in 2003.

Are police investigating?

Twenty police forces have opened investigations into the claims.

They are:

Devon and Cornwall, Warwickshire, Avon and Somerset, Essex, Norfolk, North Yorkshire, Dorset, Staffordshire, Greater Manchester, North Wales, Cambridgeshire, Hampshire, Cheshire, West Midlands, South Wales, Dyfed-Powys, Scotland Yard, Police Scotland, Northumbria Police and Derbyshire Constabulary.

Which other organisations have acted?

A dedicated sexual abuse helpline, set up by the NSPCC and supported by the FA, received 860 calls within the first three days of its launch.

The organisation made more than 60 referrals to a range of agencies across the UK.

That was more than three times as many referrals as in the first three days of the Jimmy Savile scandal, the charity said.

The chief executive of funding body UK Sport has said if any sport did not take enough action to deal with the issue of abuse it would reconsider its funding.

The national child abuse inquiry is considering whether to investigate abuse in football as part of its overarching probe, culture secretary Karen Bradley said.

How widespread could abuse be?

Former Tottenham midfielder Stewart has said the sport could be facing a crisis on the scale of the Jimmy Savile scandal.

After his death, former DJ and television presenter Savile was found to be a prolific sexual predator.

PFA Scotland's chief executive Fraser Wishart said it would be "naive to think" the allegations were unique to one part of the UK and urged players of all levels to report any claims of abuse.

Have you been affected by the issues raised in this story? You can email haveyoursay@bbc.co.uk with your experience.

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