3:00pm: Federated Mountain Clubs is feeling vindicated after the Ombudsman's finding on a complaint against DOC.

The Ombudsman has upheld a mountaineer's complaint that the Department of Conservation unlawfully granted a concession on the Routeburn Track.

It comes after DOC allowed a 66 percent increase in overnight guided walkers.

Federated Mountain Clubs president Robin McNeill says certain DOC officials have been cavalier in approving concessions in public conservation lands, that fly in the face of management plans.

The Department of Conservation says it's considering the report by the Ombudsman.

DOC's Deputy Director General of Policy, Doris Johnston, says the report raises some interesting questions that they now want to talk with the Otago Conservation Board and Conservation Authority about.

It expects to respond to the Ombudsman in the New Year.

Meanwhile existing guiding operations on the Routeburn will continue as normal.