From the Telegraph:
The Wellington-based museum, known as Te Papa - a Maori name that translates as "Our Place" - said it was imposing the rule as a condition demanded by tribes that had provided some of the items.
The "stay away" warning went out to staff from regional museums who have been invited to a behind-the-scenes tour of items not usually on display to the public.
Jane Keig, a spokesman for Te Papa, defended the museum's stance, saying some of the taonga, or treasures, "have been used in battle and to kill people".
She said Maori believed that each taonga had its own wairua, or spirit, inside it.
Maori tradition dictates that a pregnant or menstruating woman is tapu, or taboo, and so are the artefacts, meaning that if the two come into contact a curse could be invoked.
"Pregnant women are sacred and the policy is in place to protect them from these objects," Ms Keig said.
Traditional Maori belief in curses, or makutu, is exceptionally strong, and in 2007 a woman drowned after relatives attempted an exorcism to rid her of an "evil spirit" they thought was possessing her.