A 22-year-old man has been arrested after a shocking Facebook page was set up lauding suspected police double killer Dale Cregan as a "legend".
The man, from Netherley, Merseyside, is being questioned over a "tribute" which went online within hours of Pcs Nicola Hughes, 23, and Fiona Bone, 32, dying in a gun and grenade attack in Hattersley, Tameside, on Tuesday morning.
Some people had chosen to use social media in a "very malicious and offensive way", Greater Manchester Police (GMP) Assistant Chief Constable Garry Shewan said.
As tens of thousands of tributes poured in from across the nation for the fallen officers, more than one Facebook page was set up in praise of the suspect held by police. One was titled Dale Cregan OBE, with internet "trolls" posting messages claiming the alleged killer was a "hero".
From looking at the numerous websites containing derogatory and offensive comments, Mr Shewan said he saw "ordinary members of public alarmed and distressed at some of the ridiculous comments that have been put on there".
It comes as the country's top prosecutor, Keir Starmer QC, said "the time has come for an informed debate about the boundaries of free speech in an age of social media".
A warrant of further detention was obtained on Wednesday night for Cregan and will expire at 9am on Friday. A 28-year-old man who was arrested on Wednesday in the Hattersley area on suspicion of conspiracy to commit murder also remains in police custody.
The Facebook arrest comes after GMP thanked the public and said officers took heart from the huge outpouring of goodwill and public support.
The force has received 33,500 messages on its online book of condolence, more than 21,000 have been posted on the force's Facebook page and more than 1.3 million people have viewed the tribute to the officers on Facebook.
Meanwhile, the BBC has pulled the final episode of its drama Good Cop following the murders. The drama, starring former Hollyoaks and Luther actor Warren Brown, features scenes of a violent attack on a female police officer. A new transmission date will be confirmed in due course.