What was his role in the death case?
In what capacity did he deal with death case while working as HR?
Is the company locate close to where employee is now working/staying?
He will have to consider all these aspects before getting involved.
Anyway without seeing all papers connected with death,he should not comment or give any evidence.
This is in addition to valid questions raised by Mr Nathrao. Whenever there is death case, company orders domestic enquiry. Why company is not referring the records of domestic enquiry? Secondly, does employer want your friend to be witness?
Tell your friend to write to his previous employer to write official letter on company letterhead. While current employer has nothing to do with this case, nevertheless, it is important for your friend to keep his current employer informed on his deposition in the court.
Your post is very cryptic and hence compels the respondents to be presumptive, I think. Anyway, the previous employer seeks now your friend's co-operation four years after his leaving means that the death case might be related to the organization like a claim under the WC Act,1923. So, there is no harm in complying with the request. However, as Mr.Rao suggested, your friend should go thru all the relevant documents relating to the case and ascertain the part played by him before hand.