Visiting New Zealand - nervous of customs

Hi there

I am writing to this forum on behalf of a friend and wonder if anyone can help. In 2004 my friend (CJ)was invited by her brother to visit her sister in the UK as a surprise.

Customs at Heathrow are extremely strict, and she was singled out at random along with another 30 other South Africans on the same flight, and after 10 grueling hours in the customs office was deported back home to South Africa. The treatment she received was harsh, humiliating and nothing she told them was believed. A security guard told her this was normal procedure in Heathrow and she was simply in the wrong place at the wrong time. Her passport also has a cross written across the page of her not entering the UK. At the time a VISA was not considered necessary, but the customs also held that against her.

Now, her best friend's husband has also invited her to visit his wife as a surprise in New Zealand, all expenses paid. Her trip is scheduled for the end of September.
Needless to say, CJ is terrified beyond normalcy of going through all that again. She has been informed once again that no VISA is required to enter New Zealand.
Is this true? Does she have reason to fear? Is there a chance she could go through this trauma all over again?

Thank you for listening, all help and advice will be much appreciated.

Kind Regards
JLeo