That is according to The Sun, who claim the swoop for the 19-year-old will go to a tribunal.
Solanke agreed to sign for the Reds on a free transfer once his contract expires at Chelsea on July 1.
The England Under-21 international rejected the chance to extend his stay at Stamford Bridge and will likely begin life at Liverpool in the Under-23s set-up when he officially joins.
However, The Sun claim Liverpool face another tapping-up row just one week after their embarrassing botched attempts at signing Southampton star Virgil van Dijk.
The Reds had to apologise to Southampton for their alleged illegal approach for the Dutch international.
And they could be in for the same sort of flak in their dealings for Solanke with the Reds set for another quizzing.
Premier League rules state that out-of-contract players can talk to domestic clubs after the third week in May.
But The Sun suggest a deal for Solanke to move to Anfield was already in place in February.
Liverpool announced that personal terms had been agreed with the striker on May 30.
Solanke has apparently already said his goodbyes to friends at Stamford Bridge.
But the timeline of the transfer could be called into question as it may have potentially breached rules over out-of-contract players.
The Sun say both Chelsea and Liverpool have declined to comment on this matter.
Both clubs are yet to have agreed on a fee so compensation will also decided at the tribunal.
Chelsea are supposedly fuming over Solanke’s transfer after losing another bright prospect to Liverpool.
The Reds snapped up 17-year-old Rhian Brewster from the Blues in 2015.
Liverpool’s reputation was tarnished last season when they were fined £100,000 and banned for signing academy players from English clubs for two years – one suspended – for tapping up a schoolboy from Stoke.
