"We depend upon the value of media rights associated with official international events to provide a majority of our income.

"It is therefore in the best interests of New Zealand Cricket not to support unofficial events, such as the ICL," said chief executive Justin Vaughan.

The inaugural ICL tournament is due to be played in October and November.

And the organisers, who are bankrolled by media baron Subhash Chandra, have already signed up a number of big names like Brian Lara and Inzamam-ul-Haq, the former captains of West Indies and Pakistan.

But India's official governing body, the BCCI, will not sanction the competition and the Pakistan Cricket Board and Sri Lanka Cricket have urged their players not to get involved.

New Zealand Cricket regard the ICL as an "unofficial rebel tournament".

Vaughan said: "Events such as the ICL could have the potential to compete with official international events and erode their value.

"Added to this, the proposed rebel league is scheduled to directly conflict with the Black Caps tour to South Africa as well as the start of our state domestic season.

"We have considered this issue carefully and have concluded that New Zealand Cricket cannot agree to release our contracted players to participate in the ICL.

"We have entered into these contracts in good faith and stand by our players through their contract period. We expect players to treat us in the same way."

Former New Zealand stars Chris Cairns, Nathan Astle and Chris Harris are thought to have attracted interest from the ICL and could take part as they no longer play international cricket.