The Vancouver police department was involved in a coverup in its handling of the case of an aboriginal man who froze to death after being dumped by police in an alley, a lawyer for the B.C. Civil Liberties Association charged Friday.

Mike Tammen told an inquiry into Frank Paul's death that the head of the police internal investigations section, Insp. Robert Rothwell, failed to take responsibility for finding out if Paul's family was misinformed about his death.

The inquiry has heard Paul's relatives in Maine and the community of Elsipogtog, N.B., where he grew up, were told the homeless man was hit by a cab and that his body was found in a ditch a month later.

However, the family was never told Paul was in police custody just before he died.

"We were at a loss as to how the family came to that conclusion,'' Rothwell told the inquiry.

"I wasn't micromanaging the investigation,'' he said, when asked about why there was such a lack of information in the file about his section's probe.

Tammen said that after doing an inadequate investigation into whether Paul's family was misled, Rothwell dismissed the complaint and then, in a letter to the police complaints commission, claimed Paul's family and band council would not co-operate with his investigation because they were pursuing a civil suit.

The inquiry heard Paul's family had no such claim.

"This is a coverup, in my submission,'' Tammen told inquiry commissioner William Davies.

Rothwell's dismissal of the family's complaints was passed on to Don Morrison, then the police complaint commissioner, and prompted Morrison to close the file.

Const. David Instant has tearfully testified that Paul was refused admission to the city drunk tank on Dec. 5, 1998, and that he then dumped the chronic alcoholic in an alley, where he was found dead of hypothermia a few hours later.

Tammen said Rothwell's section didn't put much effort into finding out what Paul's family had actually been told or by whom while it conducted its investigation in the spring of 2002.

Tammen said the department's investigation was hardly exhaustive, as Rothwell has claimed, and that there were no records of any communication with Paul's family, except for a small note saying the man's half-brother had been notified on Jan. 11, 1999.

However, there's no information about who would have talked to James Ackerman or what he was told by either the police department, its coroner's liaison or the local RCMP detachment in Elsipogtog, the inquiry heard.

"This officer has to bear responsibility for the inadequacies, and he was exercising a quasi-judicial function when he purported to summarily dismiss the first complaint,'' Tammen said of Rothwell.

"Now he's urging the police complaint commissioner to confirm that summary dismissal and in my submission he had a duty to do more.''

Rothwell told the inquiry he wasn't the one conducting the investigation and that Paul's family should have remembered who called them.

He said he was satisfied his section did a comprehensive job in its probe of whether Paul's family received incorrect information.

However, Rothwell said that if any of Paul's relatives felt they were deceived, the information may have been circulated to them by other family members or even the RCMP detachment in Elsipogtog.

David Dennis, vice-president of the United Native Nations Society, said outside the inquiry he's concerned that lawyers for the Attorney General's Ministry are arguing the ministry should have prosecutorial immunity at the inquiry.

Dennis said he wants Attorney General Wally Oppal to withdraw the application so prosecutors and other staff in the criminal justice branch can be called to testify about why Instant or any police officer was ever charged in Paul's death.