Dear Mrityunjay,
There are few things to be noted here:
a) Death of worker happened while on duty
b) Death happened in the course of his work. I do not know whether it can be classified as "occupational hazard". However, it was not due to some chronic disease like heart disease etc
c) Post mortem report also shows that death happened due to suffocation and suffocation happened during the work.
Therefore, prima facie, we can infer that the death of workman is attributable to the employment. But then why your enquiry committee has given any contrary report? Did he fail in observing any safety precautions? If yes, then what was that? What kind of safety training he was given? When it was given and do you have evidence of training? What about your SOPs? Did his action was contrary to any laid down SOP?
ISO certification has nothing to do with the workman's compensation, please note.
Has workman's kith and kin approached you for the compensation? If yes, did you turn down the compensation? I recommend you keeping in the loop labour officer of your area. Have you sent the copy of the findings of enquiry report to the labour officer? Has he endorsed the findings?
All these questions are from legal point of view. From the organisation's culture point of view, I recommend you giving his dependants the legally admissible dues. If you fail to do that then perceptions of the employees towards the company will change and they will start looking down upon the management.
You may not pay the compensation provided that worker had failed to observe the safety precautions or there was evident transgression of the laid down SOP. In such case it may send a signal to one and all on how important the safety guidelines are what happens when workers do not observe them.
Thanks,
Dinesh V Divekar