ferguson mike brown
A police officer standing watch as demonstrators protest the shooting death of teenager Michael Brown conceals his/her identityScott Olson / Getty Images

Anonymous has followed through on its threat to release the name of the Ferguson police officer who it claims shot dead teenager Mike Brown on Saturday.

The hacktivist collective threatened to release the name on Wednesday but said it was holding back the name before it confirmed the identity of the police officer with a second source.

However on Thursday morning the group published the name of a Ferguson police department officer it claims shot 18-year-old Mike Brown on Saturday.

The name of the officer was released by the @TheAnonMessage Twitter account but the claims have been denied by the St Louis County Police department.

Joel Currier, a reporter for the St Louis Post has tweeted that the police say the name released by Anonymous is false and that officer is not an officer from Ferguson or St. Louis.

The spokesperson added that emails and websites associated with the department were offline as a result of a cyber attack but these have now been restored and there were no known penetrations.

The group has added that it will release more information about the officer in the coming hours if the St Louis County police department - which is investigating the shooting - doesn't take action.

The group claims it will release a photo of the officer at 10am local time (4pm GMT) on Thursday, with the officer's address released at 12pm local time and if there is no response it will release a "full dox" at 2pm local time.

The hacktivist collective has also released personal information about St Louis County Police Chief Jon Belmar on text-sharing website Pastebin including his address, social security number, phone number and date of birth.

Threats

The Ferguson police said on Wednesday that it would not reveal the name of the officer who shot the teenager after threats were made against that officer.

Brown was shot dead by a police officer while out walking with a friend on Saturday.

Police claim Brown struck the officer in question and tried to steal his gun. Brown's friend claimed to reporters the officer told them to move on to the footpath before threatening Brown with the gun.

The incident has led to four days and nights of demonstrations on the streets of Ferguson, with police resorting to using tear gas and rubber bullets on Wednesday night.