Chelsea's signings of Willian and Samuel Eto'o in 2013 are part of the Premier League's investigation into the club over possible breaches of financial regulations, sources have confirmed to ESPN.

ESPN reported in August that the club were being probed after Chelsea's new owners Todd Boehly and Clearlake Capital flagged a number of transactions to the game's governing bodies as part of the due diligence process in completing their takeover last May.

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That led to Chelsea being fined 10 million ($10.65m) by UEFA in July for submitting incomplete financial information relating to multiple deals between 2012 and 2019.

The Premier League are yet to conclude their own process but, as first reported by the Times, sources have confirmed to ESPN that the deals which brought winger Willian and former Cameroon striker Eto'o to Stamford Bridge are part of the investigation.

Chelsea signed Willian 10 years ago after securing a last-minute agreement for the player when he had been poised to sign for Tottenham. A couple of days earlier in that summer window, Eto'o arrived on a one-year contract. Both players joined Chelsea from Russian side Anzhi Makhachkala.

Willian is now playing for fellow west London club Fulham while Eto'o retired in 2019.

Abramovich, who bought the club in 2003, was forced to sell Chelsea last year after he was sanctioned by the UK government for alleged links to Russia president Vladimir Putin.

"These allegations pre-date the club's current ownership. They concern entities that were allegedly controlled by the club's former owner and do not relate to any individual who is presently at the club," Chelsea said in a statement on Monday.

"Chelsea FC's ownership group completed its purchase of the club on May 30, 2022. During a thorough due diligence process prior to completion of the purchase, the ownership group became aware of potentially incomplete financial reporting concerning historical transactions during the club's previous ownership.

"Immediately following the completion of the purchase, the club proactively self-reported these matters to all applicable football regulators.

"In accordance with the club's ownership group's core principles of full compliance and transparency the club has proactively assisted the applicable regulators with their investigations and will continue to do so."