Everton have signed Chelsea striker Romelu Lukaku in a club-record £28million deal.

The Belgium international, who spent last season on loan at Goodison Park and was their leading scorer with 16 goals in 33 appearances to help them finish fifth, has agreed a five-year deal.

Lukaku was manager Roberto Martinez's primary summer transfer target and while the fee may have blown their previous record - £15m for Lukaku's compatriot Marouane Fellaini when he moved from Standard Liege in 2008 - the Toffees boss believes the striker's age and potential mean it was worth paying.

Martinez said: "This signing is not just important for this season. It is a significant day in the history of this football club."

After signing his contract at Goodison, Lukaku said: "I'm 21, I need to be playing in a good team. I needed to be in a place that felt right.

"I had a feeling that this was the best place for me to grow, so I'm happy to be here again."

Meanwhile, referees in English Premier League matches next season will use the vanishing spray that came to prominence in the recent World Cup in Brazil, it has been announced.

The 'magic spray' will be used at free-kicks to mark out where the wall should stand 10 yards away from the ball and has been shown to prevent encroachment and speed up play.

The spray will also be used by Uefa in the Champions League and Europa League - it lasts around a minute before it disappears.