A long-standing Canterbury tourism company will have to shut down after the American owner of Flock Hill Station has revoked its access rights.

High Country Explorer Tours has been operating in Flock Hill station for 23 years.

American company Coast Range increased its stake in the station from 24 percent to 100 percent, following an application to the Overseas Investment Office in 2010.

It has now told High Country Explorer Tours it can no longer use the land, spelling the loss of employment for its 16 workers.

Managing Director Rod Bennett says their business proposals were rejected.

"And eventually decided to cancel our access, no reason has been given. The thing that we're disgruntled about is the Overseas Investment Office were not informed about our activity on the property."

Mr Bennett says the company has built a huge international profile over the years.

"So highly beneficial to the product of the Canterbury region. New Zealand's now in a very embarassing situation because we have confirmed bookings with the world's largest cruise ship lines, and we can't fulfil our product now."