With a quarter of the match to go Gerrard and Brown chased a ball towards the penalty area but, as the Pompey midfielder tried to hold off the England international, Gerrard seemed to hit his opponent with his forearm.

Referee Stuart Attwell was only a few yards from the incident but took no action against the Liverpool captain.

Only a week ago, Gerrard found himself in a similar situation for an alleged V-sign made at referee Andre Marriner in the defeat at Wigan.

That went no further as the official said he had seen the incident at the time and decided it did not warrant any action, but Attwell will almost certainly be asked to look at this incident again by the Football Association.

However, manager Rafael Benitez is confident his captain will escape further punishment.

"I don't think so," said the Spaniard when asked if he was worried about retrospective action against his captain.

"I haven't seen it but I was asking and I think it was nothing."

Benitez also played down his immediate substitution of Gerrard, adding: "We were thinking of changing (Fernando) Torres, Glen Johnson and Gerrard and we did it."

Portsmouth manager Avram Grant said he also did not see the incident but felt referee Stuart Attwell should have spotted it.

"I didn't see it. I will speak with Michael Brown and then I will tell you," he said.

"They told me the referee was four metres away from this so I think the referee needs to see from four metres what I didn't from 40 metres," he said.

"Personally I like Steven Gerrard. I think he is a good player and a fair player."

The incident overshadowed what was Liverpool's biggest victory since late September as Torres scored his 14th and 15th goals in the Premier League this season, with Ryan Babel and Alberto Aquilani - registering his first strike for the Reds - also on target before Nadir Belhadj's late consolation.

"It was a good game. We were trying to play well for the fans and score goals," added Benitez, whose side moved within a point of fourth-placed Tottenham.

"It was an important goal in an important week.

"It was really good for Aquilani and really good for the team. He has shown he has quality and he will have more confidence and that is good.

"We have seen a lot of players playing well today and that is good for me because it gives me more [selection] problems."

Grant refused to lay the blame on goalkeeper Jamie Ashdown, whose clearance straight into Gerrard set up Torres' first goal.

"Jamie is a good goalkeeper. I will not speak about mistakes because it is part of the game," he added.

"We started the game okay, we played how we wanted to play and then came the first goal and we lost our shape. They scored a second and third goal in seven minutes and the game was finished."