Derby County have reportedly triggered the buy-out clause in Tom Ince's Hull City contract as they pursue the England Under-21 international.
Ince, 23, scored 11 goals in 18 appearances on loan with the Rams during the second half of last season and there is believed to have been an option to make the move permanent.
New head coach Paul Clement is said to be keen on signing the winger and ready to part with a club-record sum.
Derby's previous record fee to sign a player was £3.5m for Robert Earnshaw in 2007 and, according to BBC Radio Derby, the Rams are willing to part with up to £6m for Ince's services.
Clement has already seen Darren Bent and Alex Pearce join the club since he succeeded Steve McClaren, who yesterday was confirmed as the new head coach of Newcastle United.
There is a year left on Ince's Hull contract and he is more likely to agree to a switch as the Tigers will be in the same league as Derby next season after relegation from the top flight.
He made nine appearances in his first season with Hull, starting only three Premier League games and scoring just once in the League Cup.