King's Lynn Town's play-off semi-final clash against Stratford Town on Wednesday is off.
The Linnets released a tweet late on Tuesday night without adding further details, although a statement is expected on Wednesday morning.
It is understood that the issue is within their opponents' camp.
A statement on Stratford's official website said: 'Wednesday's play-off semi-final v Kings Lynn has unfortunately been postponed and we will keep you all updated when we hear further from the FA.
'We have received a letter from the FA on April 29 regards an alleged ineligible player and potential points deduction. The FA asked us to supply relevant information by lunchtime April 30 which we will comply with.
'We await the outcome from the FA and sincerely apologise for the inconvenience caused and we hope a swift conclusion.
'The club will make no further comment until we have heard further from the FA.'
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