Preston North End have been named as one of the 11 clubs to write to the EFL asking for an in-depth inquiry into the Leeds United ‘spygate’ controversy.
Elland Road head coach Marcelo Bielsa has admitted sending staff to watch opposition training sessions with the next move from the authorities awaited.
On Wednesday night The Times published the letter from Championship clubs which requests “full disclosure” about the scouting trips including times, dates and any financial details.
As well as PNE - Derby County, Norwich City, Bristol City, Nottingham Forest, Middlesbrough, Hull City, Swansea City, Brentford, Blackburn Rovers and Millwall are named as signatories of the letter sent last Friday.
The EFL and FA are looking into the matter which arose when Derby were forced to halt a training session on discovering a member of Leeds’ staff watching on the day before their game earlier this month.
Bielsa admitted he was behind the move and then held a 66-minute media briefing, including a PowerPoint presentation, in a bid to fully explain his analysis techniques and demonstrate there was more to his methods than ‘spying’.
The 63-year-old Argentinian was interviewed by the FA on Monday.
PNE have played Leeds twice this season, winning 2-0 at Elland Road in the Carabao Cup in August before losing 3-0 in the league at the same venue three weeks later.
The sides meet at Deepdale in April.
North End boss Alex Neil spoke on the issue last week, saying that while it was not in the spirit of the game that a serious punishment wasn’t called for.
“I don't think it's normal practice in this country and I don't think it's sportsmanlike behaviour,” he said.
“What amazes me is that he's just come out and said he's done it, said he's been doing for a while and doesn't make any apologies as if he's not going to continue doing it.
“It's bizarre and if you ask any manager in this league or any other league 'would you mind that the opposition manager is going to come and watch your training session before the game starts', the answer would be yes.
“I think it's a little bit underhand.
“I should be a wee wrap on the knuckles and a 'listen, don't do that again'.”
West Bromwich Albion, Sheffield United, Sheffield Wednesday, Rotherham United, Birmingham City, Aston Villa, Queens Park Rangers, Bolton Wanderers, Stoke City, Wigan Athletic, Reading and Ipswich Town have not backed the letter.