A man killed in an explosion at a takeaway was an employee of the shop, detectives said.
The body of 40-year-old Fiaz Ahmed Ansari was discovered in the rubble of Kams King of the Grill, a kebab shop, in Narborough Road, Leicester on Monday.
Detectives launched a murder inquiry following the explosion, which happened in the early hours.
Emergency services received reports of the explosion around 2.23am and the body of Mr Ansari was found during a site clearance later the same afternoon.
A spokesman for Leicestershire Police said a post mortem examination has been carried out but the cause of death has not been released.
He added: "Six people, two men and four women, arrested in connection with the incident remain in police custody after officers obtained from Magistrates a warrant for further detention."
Detective Superintendent Mark Harrison, who is leading the investigation, said: "We would like to speak anyone who may have visited Kams King of the Grill during Sunday evening (August 28).
"Whether it was for a social visit or to buy food from the shop, it is important we speak to you.
"Also if there is anyone who knew Fiaz and may have seen him, had been contact with him or knows of his movements during that same evening, we would ask they contact police."
Anyone with any information is asked to contact Leicestershire Constabulary on 0116 222 2222 and quote incident 103 of August 29 or call Crimestoppers anonymously on 0800 555 111.