Carragher has been pictured standing on a barrier and arguing with supporters in an executive box after the Reds' FA Cup third-round draw at Kenilworth Road.
But Liverpool, and it is believed the Football Association, will not be taking any action against the 30-year-old defender.
It is being claimed the incident occurred after the players' warm-down, when they were signing autographs and shirts for young fans.
A club spokesman said: "At the end of the warm-down, Jamie went back to sign autographs for youngsters in the executive boxes.
"Unfortunately, he was subjected to a tirade of foul-mouthed abuse and also had beer thrown at him."
A Liverpool club source added: "He probably would have been wiser not to get involved, but there is only so much that any human being can take."
Luton-born Simon Lamport, who was with his son in a nearby executive box, said: "I witnessed what happened and it is nothing like what is being portrayed.
"I was in the executive box with my son a couple down from the one where it all happened.
"All the other fans had gone, but Liverpool players were jogging round the pitch. Afterwards, those players had come across to sign programmes, shirts and so on for the fans, including my son.
"But there was a group of Luton fans who had been dressed up in wigs as Scousers, and they started taunting Jamie Carragher.
"Then what looked like spit, or maybe it was beer, was aimed at Carragher. Yes, he did jump up onto the barrier to talk to them.
"He was not led away by security staff, or anything like that, and then he jumped down again.
"He could easily have gone straight into the executive box, but did not. But the eight or so fans in the box backed away pretty quickly. There were references also to Carragher's family.
"What happened to him was completely out of order. I don't think players should have to put up with that sort of thing, especially when they have come across to kindly sign autographs and talk to the youngsters.
"I'm not a Liverpool fan, I was born and brought up in Luton, but the way this has been portrayed is not right."