A sixth man has been arrested by police investigating the shop explosion in Leicester that left five people dead.
Three members of the same family died when the building on Hinckley Road was destroyed last Sunday.
The arrested man, who is in his 40s and from East Anglia, was being held on suspicion of manslaughter on Sunday.
Three men have been charged with manslaughter and arson with intent to endanger life. Two other arrested men have been released under investigation.
The blast happened at a Polish supermarket in the city's Hinckley Road just after 19:00 GMT.
Mary Ragoobar, 46, and sons Shane, 18, and Sean, 17, lived in the flat above the shop.
Five people were also taken to hospital after the explosion, one of whom suffered critical injuries.
Sean and Shane Ragoobeer, along with Shane's girlfriend Leah Beth Reek, 18, and Viktorija Ijevleva, 22, who was working in the shop at the time, were officially named on Friday as among the dead.
The fifth body is still to be formally identified but is believed to be Ms Ragoobar.
Aram Kurd, 33, of Hillary Place, Leicestershire, Hawkar Hassan, 32, of Eld Road, Coventry and Arkan Ali, 37, of Drake Close, Oldham, are due to appear at Leicester Magistrates' Court on Monday.