Collymore reported receiving racially abusive and threatening tweets between January and May.
On Monday he tweeted:
Cannock and Staffordshire Police have been exceptional. It's Twitter refusing to give info. Twitter, beyond UK law. For now.
— Stan Collymore (@StanCollymore) July 28, 2014
Staffordshire police said it had spoken to four teenagers who sent racist and threatening tweets to the ex-footballer but it had been unable to track down other abusive users after Twitter failed to supply their details.
Ch Ins Steve Morrey, commander of Cannock Chase local policing team, said: “A thorough and detailed investigation was launched by Staffordshire police following the abuse directed at Mr Collymore on Twitter earlier this year.
“After inquiries were carried out four juveniles were located and dealt with through restorative justice. Mr Collymore was aware of this and happy with the process. Despite repeated requests for information made to Twitter regarding a number of other users we wanted to speak to in connection with this matter Twitter have not supplied it.
“We have also tried to obtain this information via other social media networks but to no avail. Therefore all lines of inquiry have been exhausted. The matter will be reviewed should any new information come to light. Mr Collymore has been regularly updated on our progress throughout this investigation and is aware of the outcome.
“We would like to reiterate the abuse directed at Mr Collymore was completely unacceptable and we all have a shared responsibility to treat each other with dignity and respect. It’s our role to investigate complaints of criminal behaviour and where appropriate take action.”
Collymore has been the repeated target of offensive and often racist tweets. In January we reported how Cheshire-based UTV Media, said it would “stop promoting Twitter and its Twitter accounts until the station feels that Twitter is responding appropriately”.