Sir Philip Otton, the chairman of the tribunal panel considering

United's challenge against their 15-point penalty, is said to be investigating a letter sent by Shaun Harvey, the club's chief executive, to other Football League clubs last month.

Dougie Freedman - 'Leeds United's form is worthy of automatic promotion: Click here for full interview.

Harvey's letter is alleged to have outlined the argument which Leeds planned to present to the arbitration hearing, which began last Wednesday and heard final submissions from both Leeds and the Football League on Monday.

A report claims the letter may have breached FA Rule K6, which insists on confidentiality surrounding arbitration cases.

However, the basis of United's argument was already in the public domain before Harvey's letter was sent, having been submitted to the High Court in February.

Leeds served a writ on the Football League on February 5, and their grievance is detailed in a 27-page claim form issued in the High Court of Justice on February 12.

Harvey told the YEP: "It wouldn't be appropriate for me to make any comment at this time."

The arbitration panel have agreed to return a verdict by May 1, two days before the final weekend of the season.

The wait for a decision has seen the Football League rule that Swansea City will not be presented with the League One title after their final home game against Leyton Orient on Saturday.

In a statement, the League said: "The panel in the hearing have committed to provide a verdict on or before May 1 and the League has been advised not to engage in any actions which might be misconstrued or viewed as pre-empting the arbitration process in any way."

* United's reserves rounded off their Pontin's Holidays League Division One East season with a 1-0 win over Darlington at Elland Road last night. Youngster Chris Ovington scored the only goal with a second half header.