An inquest into the death of Mzee Mohammed has been adjourned until November.
The 18-year-old from Toxteth died in police custody after being detained by security staff at Liverpool One last month.
Merseyside Police immediately referred themselves to the IPCC (Independent Police Complaints Commission) following the incident.
A ruling from the police watchdog on whether an external body will investigate the circumstances behind the teenager’s death is expected next week.
But coroner Andre Rebello has ruled that the case will not be reopened until November 11 due to the numerous parties currently involved.
He said: “I understand that Merseyside Police would not be averse to another force being brought in to investigate.
“What I can’t have, is the handcuffs of statute stopping the IPCC investigating everything to the same standard.
“The IPCC doesn’t have the resources to investigate other parties.”