The family of a young man who collapsed and died after being restrained outside a bar in Manchester have said the local police have not "supported them".
Julian Webster's relatives say they have lost confidence in Greater Manchester Police and want their own force in Birmingham to get involved.
The 24-year-old, from Birmingham, died in hospital, shortly after the incident outside the Pitcher and Piano in April.
A police spokeswoman said they had been dedicated to the investigation.
Det Insp Mark Roters said: "The initial post-mortem examination was inconclusive and we are now awaiting results from further tests to try and establish a cause of death.
"This is a complex investigation but we are committed to finding out what led to the tragic death of this young man."
However, Mr Webster's auntie Carmen McFarlain, said: "We have had little contact with Greater Manchester Police and we feel terribly let down.
"We, as his family, do not know anything, we have been told that the post-mortem examination proved inconclusive and that is all.
"We had a family liaison officer assigned to us for the first week but then he went on holiday. Since then, we were given a number but we were out through to the detective leading the case and he wasn't able to help us. We are talking almost two months after Julian's death and we do not feel supported."
A GMP spokeswoman added: "In the recent absence of the family liaison officer due to a pre-booked holiday, contact details for another officer were provided and the family were also referred to Victim Support in Birmingham.
"The investigative team have spoken to the family on a regular basis and will happily respond directly to them in relation to any concerns they have."
They family have complained to their local councillor in Birmingham, Sir Albert Bore, who has contacted West Midlands Police.
A spokeswoman on behalf of Sir Bore said: "He has written to West Midlands Police Force asking their officers to liaise with Greater Manchester Police.
"They wrote back to him confirming that they had written to them."
Ms McFarlain added: "Our world was shattered when Julian died and shortly after his death we were just in shock, we couldn't handle it.
"We are now beginning to get things back together and have been to our local church and different support groups to help us through."
Two men aged 25 and 29 were arrested on suspicion of murder have been bailed until 29 June 2009 pending further inquiries.