Blackburn boss Sam Allardyce was left fuming by his side’s abject performance in the 3-0 defeat, and now he has the added problem of this latest allegation against the controversial Senegal international.

Diouf was interview by police, accompanied by a Blackburn official, in a private room at Goodison Park an hour after yesterday’s match.

The Senegalese international was seemingly involved in an altercation with the ball-boy during the first half.

Diouf then suffered abuse from home fans, and again when he went to take two corners in the area of the original incident.

A police spokesman said: “Merseyside Police are looking into an allegation that a 28-year-old man used racist language at the Everton match today.”

The ball-boy lodged his complaint with his ground supervisor, who in turn told Everton officials, who then informed the police.

With Blackburn dropping into the relegation zone, this is the last thing Allardyce needed.

After the game he was scathing of his team’s display. Everton strolled to victory with two goals from Louis Saha and a third from defender Joseph Yobo.

Allardyce will now make changes for tomorrow’s Carling Cup tie at Nottingham Forest and insists shirts are now up for grabs against Aston Villa in the league next weekend.

He said: “No player deserves to keep their shirts for the midweek Carling Cup game(at Nottingham Forest), apart from Chris Samba and Paul Robinson.

“The team defended poorly after we had worked hard on the training ground to counter what Everton do.

“(Everton full-back) Leighton Baines has a good delivery from wide areas, we worked on those things and they did not seem to take any notice of any of that.

“Steven Reid and Brett Emerton will both come into the team on Tuesday night for the cup tie. And I can promise that whoever plays well at Forest will keep the shirt for the next Premier League match.”

Everton boss David Moyes can now start to see signs of Everton hitting the form which impressed so many last term.

He said: “We are improving, there were the signs of the style that we were starting to show last season. But we are still a bit sticky, I am still looking to get things better.”

Moyes was delighted with Saha, who has now hit six goals already this season.

The Goodison Park chief added: “We signed Louis when we were very short of forwards through injury, and he had been having his own injury problems. Many people said it was a bit of a gamble.

“But his ability is outstanding. I have not worked with that many players with that sort of quality. Louis is right up there with the best I have ever managed. A lot of people beforehand had signed him for his talent and goals.

“Louis wants to prove that he is not injury-prone, like lots of people said he was, when he came here.”