DETECTIVES have been granted more time to continue questioning a man arrested on suspicion of murdering father-of-four Robert Johnston as he walked home from a night out in Bolton town centre.

The 25-year-old man, from the Halliwell area, was arrested at his home on Thursday following a call from a member of the public.

Magistrates yesterday approved a police request to allow them to interview him for a further 36 hours.

Mr Johnston died from head and facial injuries eight hours after being attacked in Saville Street as he walked home to his house in Levens Drive, Breightmet.

Detectives have revealed that Mr Johnston and his friend Darren O'Donaghue got into an argument with two men at 2.45am last Saturday as they walked home from the town centre, where they had been drinking on Friday night to celebrate Mr Johnston's 39th birthday.

Mr O'Donaghue, aged 38, of Holme Avenue, Bury, was also injured but refused hospital treatment.

Despite the arrest, officers last night toured the Bradshawgate area of Bolton town centre, where Mr Johnston and his friend had been drinking, in a bid for more information on the killing.

Posters urging drinkers and clubbers to come forward were shown last night. On them was a picture of Mr Johnston, who was a demolition firm foreman.

Police also showed CCTV pictures of the two men they wanted to question in connection with the attack. They are said to be either the attackers or important witnesses who detectives are keen to speak to. Only one of the men is said to have attacked Mr Johnston.

Det Supt Bottomley said it was still crucial for anyone with information to contact police. "We would still like to speak to anyone who has any information," he said.

Anyone with information is asked to contact the incident room at Castle Street on 0161 856 5965 or Crimestoppers on freephone 0800 555 111.