Police investigating the murder of barman Stuart Walker have arrested an 18-year-old man.

The man, who was taken into custody on Thursday evening, is expected to appear at Ayr sheriff court today.

Mr Walker was found dead with “horrible” injuries near an industrial estate in Cumnock on Saturday 22 October. He had been beaten and burned.

Last week, it was reported that Mr Walker had been questioned over an alleged indecency incident involving a 12-year-old boy.

However, the Daily Record reported that prosecutors planned to throw out the case because the claim appeared to be “utter nonsense”.

The allegation was made by a 44-year-old man whose son was the alleged victim. The man claimed Mr Walker had put his hand down the boy’s trousers.

The man cannot be identified to protect the identity of his son. But the Record reports that he has a long criminal record including rape, theft and assault.

A Crown Office source told the newspaper that Mr Walker had urged the man’s girlfriend to leave him and the allegation was made in revenge.

The source said: “There was absolutely no corroboration for the allegation. It appeared to be utter nonsense and was going nowhere.

“Stuart has no history of such offending. He has a couple of motoring offences but that’s it.”

Another source with knowledge of the claims said the accuser was regarded as a trouble-maker and had seen Mr Walker as “an easy target” because of his sexual orientation.

While thousands of people expressed sympathy on microblogging site Twitter, some posted extreme anti-gay remarks leading to at least one account being shut down.

The user, @mabsmiller, wrote: “I think it’s great what happened to Stuart walker better dead now than infecting people with #Aids.”

In another, @mabsmiller wrote that Mr Walker “got what he deserved” and would “burn in hell”.

The account is no longer active, though it is not known whether it was removed by its owner or Twitter administrators.