The English Football League has said it needs more time to complete the investigation into the Leeds ‘spygate’ furore.

Leeds boss Marcelo Bielsa admitted to having all his Sky Bet Championship rivals watched in training after a member of his staff was caught in the act by Derby last month and the EFL and Football Association launched a dual investigation.

“At its meeting on Friday afternoon, the EFL Board (*excluding representatives of the Championship) considered the matter of the incident in the vicinity of Derby County’s training ground on Thursday, January 10,” the EFL said in a statement.

“Following a comprehensive review of all available evidence, it was determined that there remain a number of areas that require further exploration and clarification and these investigations will take place at the earliest opportunity.

“An update on this matter will be provided following receipt and analysis of those subsequent enquiries and until this point no further comment will be made.”

Derby made a formal complaint to the EFL after a man, later confirmed to be an employee of Leeds, was moved on from the perimeter of their training ground by Derbyshire Police.

The incident occurred 24 hours before Leeds beat promotion rivals Derby 2-0 at Elland Road. Bielsa admitted he was behind the spy tactics and had called Derby boss Frank Lampard to accept full responsibility.

Bielsa defended his methods, insisting they were not illegal, and called a hastily-arranged media briefing six days later to present his in-depth analysis in the hope of showing his research is so thorough that he gained no advantage from watching Derby train.

Derby, Bristol City and Norwich were among 11 Championship clubs to have signed a collective letter sent to the EFL demanding a full inquiry.

Bristol City owner Steve Lansdown had called for Leeds to be given a points deduction, while Norwich’s sporting director Stuart Webber said his club wanted clarity from Leeds over their actions, but did not think they should have been punished.

Responding to Friday’s EFL statement, Leeds said in a statement on their website: “Leeds United acknowledge the statement made by the EFL this evening regarding an incident at Derby County’s training ground in January.

“We understand the EFL’s need to request more time to investigate the complaint further and we will continue to cooperate fully as we look to resolve the matter quickly.”