Swansea - A Swansea University student, 21, from Pontypridd, south Wales, is alleged to have tweeted: 'LOL [Laugh out loud]. **** Muamba. He’s dead!!! #haha.' When other users objected, he is said to have launched a volley of vile racist and sexist abuse. Later, the undergraduate posted tweets saying the remarks were not his and insisting he was not a racist. He claimed his account had been hacked and he hadn’t had access to his phone at the time the remarks were made. South Wales Police released a statement confirming the arrest of a man for making "racially offensive" comments on Twitter. Police forces throughout the UK regularly take action against those who use Twitter to express racially offensive remarks. The man is currently being held in custody at Swansea Central Police Station.Muamba, 23, is fighting for his life in hospital after suffering a heart attack and collapsing during Saturday's FA Cup tie at White Hart Lane.