A Conservative councillor was arrested over a message on his private Twitter account calling for a newspaper columnist to be stoned to death, police said today.
Gareth Compton, councillor for Erdington, Birmingham, was questioned and released on bail following his arrest last night.
A spokeswoman for West Midlands Police said: "We can confirm a 38-year-old man from Harborne has been arrested for an offence under section 127 (1a) of the Communications Act of 2003 on suspicion of sending an offensive or indecent message.
"He has been bailed pending further inquiries."
The post on Mr Compton's profile on the micro-blogging site, which has since been removed, reportedly read: "Can someone please stone Yasmin Alibhai-Brown to death? I shan't tell Amnesty if you don't. It would be a blessing, really."
In a message posted on the site this afternoon he apologised: "I did not 'call' for the stoning of anybody. I made an ill-conceived attempt at humour in response to Yasmin Alibhai-Brown saying on Radio 5 Live ... that no politician had the right to comment on human rights abuses, even the stoning of women in Iran.
"I apologise for any offence caused. It was wholly unintentional."
Ms Alibhai-Brown is a columnist for The Independent.
A Birmingham City Council spokeswoman said: "Any written complaints will be formally considered by the council standards committee to determine if any investigation should be held.
"The committee will also be mindful of any criminal investigations concluded by the police."
Roger McKenzie, Unison West Midlands regional secretary, said: "Unison have been inundated with complaints from Birmingham City Council staff who are outraged at these appalling racist comments from their political masters.
"Birmingham is a multicultural city and the council's workforce reflects this.
"It is clear that councillor Compton is out of touch with both his city and the council staff. It is wholly unacceptable for a public official to make such racist comments. Councillor Compton must resign his seat immediately.
"If a council worker would have made such a statement they would quite rightly be disciplined.
"If councillor Compton won't resign his seat then councillor Whitby and David Cameron should do the honourable thing and force him to quit rather than try and defend the indefensible."
The Conservative Party said Mr Compton had been suspended indefinitely over the alleged tweet.
A spokesman said: "Language of this sort is not acceptable and as a result Gareth Compton's membership of the Conservative Party has been indefinitely suspended pending further investigation."
Birmingham City Council and Conservative group leader Mike Whitby said: "These comments were unacceptable and the party has taken decisive action on this matter by suspending the individual, which we accept and agree with.
"As a matter of course Cllr Compton has been suspended from the Conservative group."
Steve McCabe, Labour MP for Birmingham Selly Oak, said: "It is staggering that the Conservative Party allowed Gareth Compton to represent the people of Birmingham in the first place.
"His despicable comments on Twitter show that he has no place in public office.
"This sorry saga calls into question the leadership of the Conservative Party at all levels, they must stop dithering and force him to resign his seat on Birmingham City Council."