The Robben Island Museum is introducing a two-tier pricing model for international visitors and South Africans, which will see a sizable hike for tourists.

It will take effect on June 1.

The museum, tour operator said this decision was "based on an annual financial analysis".

"We believe that this decision will have a positive turnaround on our long-term financial sustainability as an organisation whilst also contributing to an increase in domestic visitors," said Blayne Crocker, chief financial officer.

Robben Island's tour promises to comprise a ferry return trip from Cape Town, transport on the Island, a guided island tour and a guided prison tour by an ex-political prisoner.

"Operationally, all of these come at an annual increased cost and has an adverse impact on revenue," the museum said in a statement.

Crocker said: "With such factors in mind, a different pricing structure that can provide for additional revenue that will meet our rising conservation needs, needed to be investigated. It is important that Robben Island Museum has the financial backing to maintain a high standard of excellence with our tour experience."

"Preserving Robben Island as a world-class heritage site requires a lot of efforts to balance the conservation of the tangible heritage elements with the mission of increasing local access to the island," added Morongoa Ramaboa, museum spokesperson.

The new standard tariffs will be:

• R550 ($40 | €35) for non-SA adults; and R300 ($15 | €15) for non-SA children aged two to 18 years.
• R380 for SA adults; and R200 for SA children aged two to 18 years.

The current price is R360 per adult and R200 each for under 18s.