Jonathan Trott and Wahab Riaz were involved in a confrontation shortly before the start of today's fourth NatWest Series match at Lord's.
An England and Wales Cricket Board spokesman has so far been able to confirm only that "words were exchanged" between the two players in the nets at the nursery end.
The incident is sure to be portrayed as symptomatic of the inevitable deterioration in relations between England and Pakistan in a one-day international series dogged by spot-fixing controversy.
The situation reached crisis point yet again this morning thanks to Pakistan Cricket Board chairman Ijaz Butt's claims that England players received "enormous sums of money" to deliberately lose the previous encounter at the Oval on Friday.
England have strenuously refuted accusations they see as defamatory and also made mention in a statement, released less than an hour before start of play, of the "legal options" which may be available to them.
Pakistan have been beset by allegations of spot-fixing against their players ever since Salman Butt, Mohammad Asif and Mohammad Aamer were named in reports of a plot to defraud illegal bookmakers during last month's Lord's Test.
An ECB statement confirmed less than an hour before the start of play today that their team were prepared to continue the series against Pakistan, despite the PCB chairman's remarks.
The altercation between Trott and Riaz - who was interviewed by police last week in the course of their spot-fixing inquiries and has played no part in this series - was brought to the attention of match referee Jeff Crowe.
It later emerged that Crowe had spoken to both players but the altercation is not thought to have been physical.
It is understood that the confrontation between the two is not directly related to the controversy surrounding Butt's comments.