The son of a murdered shopkeeper today said his death was "heartbreaking" as he appealed for information to help find whoever killed his father.

Javaid Ali, 48, was stabbed on June 15 in Sunshine Grocers in Green Road, Paisley, Renfrewshire.

He died in the town's Royal Alexandra hospital on June 29.

Today, Abbas Ali, 25, one of his three sons, paid tribute to his father and urged anyone with information about the murder to contact police.

Mr Ali said: "Our family is absolutely devastated at the loss of my father, Javaid Ali.

"He was a wonderful father, husband, son and friend. He meant so much to us and it is heartbreaking to know we will never see or speak to him again.

"I cannot put into words the suffering this has caused our family and it will take a long time for us to come to terms with what has happened.

"As a father, I could not have asked for more. My dad was an exceptionally hard worker and a great provider for our family.

"He always put our needs first and did his best to provide my brothers and I with opportunities that he did not have when he was younger."

Mr Ali described how his father was an integral part of the community and showed "genuine warmth and kindness" towards those who were less fortunate and vulnerable.

He added: "I was fortunate in that if I ever had a problem or an issue, I was able to rely on my dad to simply make things okay.

"Therefore, the brutal manner in which he was taken from us is very difficult to accept. I cannot bear to imagine the pain he might have been in when he was attacked."

More than 60 officers are currently working on the inquiry and have visited 700 homes and taken up to 170 statements so far.

Detectives are still trying to trace a man who was seen walking from the direction of Sunshine Grocers at about 3pm on the day of the incident and a young woman carrying Aldi shopping bags.

She was walking towards Green Road in the direction of the cycle track.

Detective Chief Inspector Duncan Sloan said: "This was a horrendous, vicious and unprovoked attack on a popular and well-respected member of the local community.

"I offer my sympathies to Mr Ali's wife, three sons and wider family who are trying to come to terms with this tragedy.

"We are still following a number of lines of inquiry and keeping an open mind as we try to establish potential motives for the attack.

"I know that Mr Ali was a popular member of that community and I'm appealing for people in that community to come forward."

Police said they will maintain a large presence in the area both to gather information and to reassure any concerned residents.