Former England striker Stan Collymore has urged Twitter to do more to combat internet "trolls" after being subjected to racist abuse.
Staffordshire Police are currently investigating a series of offensive messages to the radio pundit.
Appearing on BBC1's Breakfast programme, Collymore said: "Today's my birthday and I would rather not be here but I am going to try to talk about this issue.
"Nothing seems to be done. Twitter are now hiding behind 'We don't discuss individual cases'."
He added: "If you disagree with a point that I make it's absolutely fine. But I shouldn't be racially abused for it, I shouldn't have somebody that tweets me two days ago saying I am going to turn up at your house and murder you."
A Twitter spokeswoman said the company was unable to comment on individual users.
However, she pointed out that targeted abuse was against its rules and the site had recently made it easier for users to report abusive messages to them.
There are "established processes" in place for working with law enforcement, the spokeswoman added.
Broadcaster Piers Morgan was also subjected to abusive tweets after he joined calls for police and Twitter to take action over the abusive messages aimed at Collymore.
The former tabloid editor tweeted:
I repeat, racist abuse & death threats both criminal offences in UK. So keep spewing it, trolls, and I will have you ALL dealt with.
Former footballer and broadcaster Stan Collymore is calling on Twitter to take action after being bombarded by racist abuse.Read the full story ›
Staffordshire Police are investigating alleged offensive, racist messages sent via Twitter to former footballer Stan Collymore. Mr Collymore contacted Staffordshire Police yesterday evening after a number of messages were sent to him.
Chief Inspector Carl Ratcliffe, commander of Cannock Chase Local Policing Team (LPT) said: “It’s everyone’s role to treat each other with respect. It’s our role to investigate complaints of criminal behaviour and where appropriate take action.
"When we become aware of complaints about potential criminal offences, we gather evidence to allow the CPS to make a decision on whether to charge or not.”
Officers have copies of the messages for detailed investigation of alleged crimes, and will be working closely with the Crown Prosecution Service.
A man has been arrested after football broadcaster Stan Collymore was allegedly racially abused on Twitter.
Northumbria Police said in a statement:
"At 9.55am this morning, Tuesday, November 27, police received a report of racist tweets and are carrying out enquiries to trace the person responsible.
"A 21-year-old man has been arrested on suspicion of publishing written material to stir up racial hatred and is currently in police custody helping police with their enquiries."
Earlier today the 41-year-old former Liverpool striker tweeted:
"Many thanks to Greater Manchester & Northumbria Police forces for their prompt response to racism on twitter."
The former footballer turned commentator Stan Collymore has threatened to stand against Aidan Burley in the General Election after his comments on Twitter about the Olympic Ceremony:
@aidanburleymp An embarrasment to the Cannock constituency.An absolute joke of an mp.Sooner we jettison you the better.
A law student will be sentenced on Wednesday for sending football pundit Stan Collymore "grossly offensive" messages on Twitter.
Joshua Cryer, who is 21, admitted the offence at a hearing earlier this month, having previously denied contravening the Communications Act.
The Newcastle University student, who lives in the Jesmond area of the city, will be sentenced at Newcastle Magistrates' Court.
Cryer, from Burnley, Lancashire, was arrested in January after Mr Collymore reported the online abuse to police.