Here is an interesting article from the specialist consultant Chris Pollard in the UK:
"There has been some industry debate (and polling) as to whether a non-contestability period should be implemented within UK life insurance. Non-contestability would prevent an insurer from investigating whether or not, a claimant provided correct application information after a specific period of time, perhaps five years from when the policy started. Some markets, notably the US, operate such a policy."
Pollard makes a case for no move to a mandatory non-contestability period. Along the way, it is interesting to contrast the UK's situation with that here in New Zealand.