According to PKR vice-president N Surendran (left), the obvious similarity was in the manner in which the Malaysian Anti-Corruption Commission (MACC), in which custody both men died, had behaved.
"It is noteworthy that the MACC behaved in a similar fashion during the investigation and inquiries into the death of (Teoh), who also died during MACC investigations on July 16, 2009.
"In both instances, the MACC participated in open attacks on the reputation of the deceased victims during the various inquiries," he said in a statement.
Surendran added that this went against the basic principle of the common law system "that court proceedings must never be used to unnecessarily defame absent parties."
During both inquests the MACC had produced evidence that both Teoh and Sarbaini were involved in graft "although (neither were) able to answer the charge or defend (themselves)."
"This was disgraceful and unimportant to the inquiry into how he met his death," he said.
Surendran's stand is consistent with that of Ahmad Sarbaini's widow, Maziah Manap,who has accused MACC lawyer Shafee Abdullah of defaming her late husband through media statements.
MACC tried to absolve itself
The PKR veep, who is also a lawyer, noted that throughout the inquest, MACC had not acted in a manner befitting its status as a key public institution.
"MACC's priority should have been to get to the truth of the matter, ensure punishment of those culpable and institute reforms to ensure public confidence and safety.
"Instead, the MACC acted like a private individual, trying to desperately clear their name by whatever means available," he said.
One of those means, he added, was to engage in "Umno-linked lawyer Shafee Abdullah (right) to 'defend' them during the inquest".
He added that the verdict of the inquest was also "unbelievable and inconsistent" as Ahmad Sarbaini had gone to the MACC Cheras office voluntarily on April 6, but is now said to have crawled out of the third floor window to leave.
"There is also no explanation as to how and why 22 hours of crucial CCTV footage was erased, which covered the period during which (Ahmad) Sarbaini died," he said.
As such, PKR is calling for a royal commission of inquiry into the death, with the scope of the RCI to include operating procedures, recruitment and training methods of the MACC and recommendations for urgent reforms.