The Film and Publication Board has decided against banning an allegedly homophobic book, but has ruled that it be sold with an adults-only age restriction.

The book, The Pink Agenda: The Ruin of the Family, was co-authored by Christian activists Christine McCafferty and Peter Hammond.

The Lesbian and Gay Equality Project (LGEP) has described the book as "the worst example of homophobic hate speech ever published in South Africa".

The board's decision, which will be gazetted later this week, follows a hearing on Friday by a three-person committee, where the publisher, Christian Liberty Books, defended the book.

The hearing followed complaints from gay activists.

Senior executive officer of the board Iyavar Chetty said on Tuesday the book would have to carry a notice that it was for sale only to people over 18.

"The committee found that it is not desirable for those under 18, who might not be able to separate fact from fiction," he said.

"The committee was concerned the book has made assertions that are questionable to say the least, and the (authors') leap from homosexuality to criminal conduct is cruel and completely without justification."

He said the book "would come close to constituting hate literature".

McCafferty said on Tuesday she had been unable to confirm with the board that the book had been restricted.

"If this report is correct, we are quite convinced there will be an international outcry on this, and we will definitely be seeking legal guidance," she said.

"This book is based on biblical principles and if it should be classified or restricted, so should the Bible.

"There are many other books and videos which are very similar to our book, written in Europe and the United States, which have been distributed in South Africa for many years.

"Will there now be attempts to restrict them?"

McCafferty said last week that attacks on the book were based on emotive hype and not on an objective and honest reading, and that attempts to censor it were "typical of homosexual activism worldwide".

LGEP spokesperson Evert Knoesen welcomed the ruling on Tuesday.

"We think it illustrates a practical commitment in South African society to implement the values of the Constitution; in particular, the right to equality and dignity."

Knoesen said the complaints to the publication board by a number of lesbian and gay individuals in South Africa showed they were prepared to stand up and defend their own rights. - Sapa