Joseph McCormick - the father of Rhys Jones's killer - has been released after being quizzed by detectives over an arson attack.
Mr McCormick, 56, who is the father Sean Mercer, was arrested over a fire at the home of Gary Kays , a gang member jailed for his part in schoolboy's murder.
After questioning over the blaze on Saturday morning in West Derby, Mr McCormick was freed on police bail.
Rhys, 11, was killed on 22nd August 2007 when he was shot as he walked home from football practice outside the Fir Tree pub in Croxteth, Liverpool.
Sean Mercer, who was aged 15 at the time of the shooting, was jailed for life for murdering Rhys after a ten week trial.
Kays, 26, was jailed for seven years at Liverpool Crown Court Kays on two counts of assisting Mercer.
A jury heard how Kays drove Mercer, now aged 18, to an industrial site to burn his clothes after the shooting.
He was one of six gang members jailed for their involvement in the crime.
Mr McCormick was often present in the public gallery during the 10-week trial.
Police received a 999 call about the fire at 3am on Saturday when a man and a woman inside the house managed to escape uninjured.
Investigations established that a "flammable device" was used to start the blaze at Kays' home in Mallard Close, West Derby.
A Merseyside Police spokesman said: "The 56-year-old man, from Liverpool city centre, was arrested on Sunday and has been released on police bail pending further inquiries."
Amanda Jones, North Wales around 2 years, 6 months ago