Private health insurers are slugging some top-tier policyholders with annual premium rises of up to 9 per cent, more than double Labor’s approved average, prompting Health Minister Mark Butler to seek fresh advice into whether funds are price gouging.

Major funds including Bupa, Medibank, HCF, and NIB have written to policyholders in the past fortnight advising them of premium hikes ranging from 7 per cent to 9.4 per cent on “gold” and “silver” policies from April 1, according to 14 letters sent by disgruntled policyholders to The Australian Financial Review.