The Southampton first-team analyst at the centre of allegations of spying was the only member of staff present in a Manager of the Month photo in March to not feature in subsequent pictures in April and May.
Daily Mail Sport revealed last Thursday that the analyst was caught allegedly filming Middlesbrough’s training from behind a tree ahead of Saturday’s play-off semi-final first leg, which ended goalless. Last Friday night, the EFL charged the south coast club with a breach of their rules.
Saints won Tuesday’s return leg 2-1 to set up a Wembley date versus Hull City, but that is now in doubt.
An independent commission will decide on the punishment by next week, leaving the date and location of the final and the identity of Hull's opponents uncertain.
Daily Mail Sport exclusively revealed on Wednesday that the individual involved has been identified as Southampton intern William Salt.
Salt, say sources, is a key part of Eckert’s first-team operation and highly valued by the German.
William Salt, circled, is pictured with manager Tonda Eckert to mark February's Manager of the Month award
The Championship play-off final could be postponed dependent on the outcome of the 'Spygate' scandal (pictured - the alleged Southampton analyst who was accused of spying)
Salt was one of 10 Southampton staff members pictured with boss Tonda Eckert at the start of March, after the German coach was named as the Championship's Manager of the Month for February.
Southampton beat eventual Championship winners Coventry City 2-1 that weekend.
Salt, however, was not present on the picture of Eckert and his backroom staff released last Thursday to mark April’s Manager of the Month award.
It was the same day that Salt was pictured at Boro's training base, before being confronted by club staff and fleeing the area after running into a nearby golf club and changing clothes in the toilet.
Salt was also the only staff member absent when Eckert posed with his backroom team when he won the divisional prize for March.
The picture was released to media on April 9.
Southampton beat play-off rivals Derby County 2-1 two days later.
Salt was absent from a photoshoot for March - despite nine staff joining Eckert for the photo
And in April Salt was not included once again - Eckert was joined by nine staff this time too
Daily Mail Sport understands the analyst, formerly of Nottingham Forest and Aston Villa, used his bank card last Thursday to buy a coffee at Rockliffe Hall Golf Club - owned by Boro chairman Steve Gibson.
The apparent slip has given rise to the possibility of a paper trail across the country, with transactions close to the bases of other Championship clubs in the days prior to playing Southampton.
Middlesbrough’s legal team are pushing for bank statements and electronic devices to be handed over as part of the case, given they could provide a paper trail of unsporting espionage around the country.
We understand that one Championship club believe they were spied on after changing manager before playing Eckert’s side in December. CCTV is being reviewed. Since being appointed Saints boss in November, Eckert's team have the second-best record from set-pieces in the Championship.
If it is proven that Southampton spied on opposition teams on several occasions, as a whistleblower is thought to have indicated in a statement to be used in evidence, then Tonda Eckert’s side would likely be removed from the competition and Boro would take their place in the final.
Ahead of the second leg of the play-off semi-final, Southampton chief executive Phil Parsons had stressed it was 'important that the full context is established before conclusions are drawn' as the club conducted an internal review.
On Thursday, the EFL provided an update on the date of the hearing, while warning the outcome of the case could 'result in changes' to the play-off final.
The EFL statement read: 'The Independent Disciplinary Commission hearing will take place on or before Tuesday 19 May. The exact date remains under discussion and is expected to be confirmed shortly.
'The Commission will issue its decision as soon as possible following consideration of the relevant submissions and evidence. As the proceedings are being conducted by an Independent Disciplinary Commission, the EFL does not control the proposed timetable.
'Notwithstanding this, the EFL continues to plan on the basis that the Championship Play-Off Final will take place as scheduled on Saturday 23 May, with the kick-off time confirmed as 4.30pm. Supporters should, however, be aware that the outcome of the disciplinary proceedings may yet result in changes to the fixture. The EFL has a number of contingency plans should they be required, which also includes consideration of any appeal process, if required.’
Southampton and Hull City both began ticket sales for the final on Friday.