Did Thatcher strike deal with Scorpions?

From the Pretoria News:

The National Intelligence Agency (NIA) has refused to comment on claims that Mark Thatcher was caught by surprise when the Scorpions arrived to arrest him because he was under the impression that he was protected by a “deal” struck with the NIA.

The claim that a deal had been struck was made in an extract from a new book on Thatcher – Thatcher’s Fortunes: The Life And Times Of Mark Thatcher – by investigative journalist and author Mark Hollingsworth, an extract from which was published in the Pretoria News’ sister newspaper, the Sunday Independent, on Sunday.