A former commissioner of the New South Wales police watchdog sought an investigation into the “systematic failure” of law enforcement to address the number of civil cases filed against officers for misconduct, claiming the force treated the millions of dollars paid in damages each year as “the cost of doing business”.

In internal memos published as part of an investigation into the Law Enforcement Conduct Commission (LECC), Patrick Saidi, described sums paid by taxpayers as a result of suits brought against police as “horrendous” and claimed the force had provided “misinformation” about the way it handled cases.

“Arguably the police have been treating damages paid in civil suits as ‘the cost of doing business’,” Saidi wrote in one memo last year.

“The cost to society both in terms of damages paid and the legal costs of the civil litigation are horrendous.”

Last week Guardian Australia reported both Saidi and the former chief commission of the LECC, Michael Adams, had been removed by the government after an investigation revealed a difficult working relationship between the pair which had “raised concerns about leadership at the highest levels” of the agency.

But documents published as part of that report reveal Saidi’s long-running concern about the number of legal complaints made against police in NSW and a lack of transparency around the way civil claims are reported.

Since 2016 NSW police has reported paying out more than $238m in legal liability but has repeatedly rejected requests for information about the cost of particular issues.

For example last week in response to questions on notice asked by Greens MLC David Shoebridge about the cost of claims made for illegal searches, the NSW Police said it was unable to provide the figure because it was not the subject of a specific tort.

Memos published as part of the investigation reveal that Saidi – one of three commissioners at the LECC – believed police officers subject to complaints were often not exposed to internal consequences and wanted to investigate the “interaction” between civil actions and the police internal professional standards command.

“[I]nsofar as whether or not matters were referred to that command, and [whether] appropriate actions [were] taken in relation to the alleged misconduct,” he explained in one memo.

Among his concerns, Saidi wrote, was his belief that officers subject to legal complaints were “given no feedback as to the illegality of any action on their part” and that unit commanders were often not informed about findings made against police.

“Up till now, commanders who have had police officers under their command have not been advised of the fact that damages or compensation monies have been paid as a result of the misconduct or unlawful actions of police officers under their command,” Saidi wrote in documents published as part of the investigation.

“It has gone so far that there [has] been a systematic failure for police officers themselves involved in the civil action to have made known to them how much their misconduct or unlawful actions have cost the taxpayer of New South Wales.”

Saidi’s memos reveal a culture of distrust and antagonism between the police and the watchdog.

He claims that police had been “disinclined to co-operate” with the LECC, had provided “misinformation” to the agency and questioned whether the watchdog could believe what it was being told by police.

“The problem has been so pervasive that one truly questions how one could expect any voluntary cooperation from the NSWPF in future, or otherwise can accept information provided by the NSWPF in the future as being accurate,” wrote Saidi who is a barrister who represented the NSW police in civil cases before joining the LECC.

The internal investigation into the LECC was launched after Saidi levelled a number of complaints against Adams, including that he ran the watchdog in an “autocratic” fashion.

Part of that complaint included Adams’ refusal to grant the investigation after the former chief commissioner repeatedly said he did not think a formal investigation was necessary.

All the complaints against Adams were dismissed, and instead, Bruce McClintock SC, the author of the report, considered whether Saidi himself may have engaged in “maladministration or misconduct” as a result of the disintegration in his relationship with Adams.

McClintock did not make a finding on that point. Saidi was removed from the LECC in January, shortly after Adams.

Last week the Guardian revealed a landmark inquiry into potentially illegal strip searches conducted on minors by police had been cut short after Adams’ departure.

The NSW police referred a request for comment to the LECC.