OTTAWA - The RCMP offered a sugar-coated version of its relations with the Canadian Security Intelligence Service and played down disputes with the spy agency during a review of the Air India bombing conducted 15 years ago, a public inquiry has heard.

Former sergeant Terry Goral testified Wednesday that the Mounties didn't want to complicate their continuing criminal investigation into the 1985 downing of Air India Flight 182 by being overly critical of CSIS.

The result was that the force submitted a sanitized brief to the Security Intelligence Review Committee -- the civilian watchdog that monitors CSIS -- when it examined the intelligence agency's role in the affair in 1992.

The brief emphasized positive aspects of RCMP-CSIS co-operation and smoothed over areas of tension, including failures to share evidence and the erasures of more than 150 wiretap tapes of key suspects.

"This was not an appropriate way to brief, as far as the so-called relationships and problems (with CSIS),'' Goral acknowledged.

"However, in the best interests of the investigation this was the least intrusive. We were forced to do a briefing and this was, in my opinion, the best way to do it.''

The review committee, in its eventual report, was critical of CSIS for its erasures of the wiretap tapes but concluded it was unlikely that any critical evidence had been lost.

In actual fact, said Goral, many RCMP investigators did not share that opinion and believed they could have uncovered valuable leads if the recordings had been preserved.

Jacques Shore, a lawyer for the families of the bombing victims, expressed consternation at the limited co-operation offered by the Mounties to the 1992 probe.

"There was information that was clearly held back,'' Shore said outside the hearing room. "SIRC was ultimately shackled and handcuffed. ... I don't think there was much hope from the start that they were going to get the full picture.''

Internal documents tabled at the inquiry show the RCMP initially opposed any kind of review and reluctantly agreed to go along only because the SIRC exercise would be less sweeping than the alternative of a royal commission.

Goral insisted the only reason for the force's reluctance was the fear that an investigation at that point would compromise efforts to gather the criminal evidence needed to prosecute those responsible for the bombing that took 329 lives.

"The more you wash this out in public ... about the strength of your evidence and weaknesses of the evidence, it gives a heads-up to the suspects.''

Shore retorted that the 1992 review involved no public testimony -- it was held entirely behind closed doors and only a censored version of its report to the government of then-prime minister Brian Mulroney was made public.

There were also indications, in the documents tabled Wednesday, that the RCMP may have been worried about letting the review committee delve too deeply into police operations.

A briefing note prepared for then-commissioner Robert Simmonds pointed out that the force had traditionally argued against being subjected to the kind of civilian oversight that the review committee exercised over CSIS.

Another memo suggested it might not be wise to rely solely on the argument that a full inquiry would undermine the separate criminal investigation.

Goral explained there was a concern among some officers that the public could conclude the Mounties were trying to block an inquiry because they feared their investigative shortcomings might be exposed.

"It could be perceived as a coverup,'' he said.

The testimony set the stage for a long-awaited appearance by former commissioner Simmonds, who had been scheduled to follow Goral to the witness stand Wednesday but saw his testimony put off for a day.

He is expected to face pointed questioning on the well-publicized turf wars between the RCMP and CSIS that hampered the investigation of the bombing.

Only one person, Inderjit Singh Reyat, has ever been convicted for his role in the plot. The purported ringleader, Talwinder Singh Parmar, head of the militant Sikh separatist group Babbar Khalsa, was killed by police in India.

Two others, Ajaib Singh Bagri and Ripudaman Singh Malik, were acquitted at trial in Vancouver in a verdict that shocked the victims' families and prompted creation of the current inquiry headed by former Supreme Court justice John Major.