Nine tattooed human heads, held by Aberdeen University for almost two centuries, yesterday began the journey home to their Maori families in New Zealand.

The full-sized preserved heads, known as toi moko, were revered by the Maoris who stored them carefully and displayed them at ceremonies.

In the early 19th century, the heads took on commercial value and many were sold and taken all over the world. They were so sought-after that slaves were sometimes tattooed and then beheaded. In some cases, tattoos were added after death to enhance the market value.

Many of the heads in Scotland were brought back by adventurers and Aberdeen University's earliest example was from a Lieutenant Reid of the Royal Navy, who presented a "head of New Zealand warrior in good preservation" in 1821. Another came from the Marquis of Huntly.

In recent years, efforts have been made to track down the heads around the world and have them, and other skeletal remains, repatriated. Some have been sent back by Glasgow and Perth and Kinross councils and by Argentina.

One head was on show in the University of Aberdeen's Marischal Museum until around 1988 when it was removed at the request of the New Zealand High Commission because the display was deemed inappropriate.

Lee Rauhina-August, the repatriation co-ordinator for the Museum of New Zealand Te Papa Tongarewa, said they had had a lot of co-operation in securing their return.

The nine Aberdeen heads will go to the wahi tapu (consecrated sacred space) at Te Papa until their iwi (tribe) of origin is discovered. They are then likely to be buried.

At yesterday's ceremony, performed below a stained glass window created last year to commemorate the toi moko, Maori elder Kukupa Tirikatene said: "They are sacred in a sense to their families. The tattoos are like an individual's coat of arms. There are still some who have them done."

Te Taru White, kaihaut (Maori co-leader) of Te Papa, said: "This is both a time for sad reflection on the turbulent journeys these ancestors experienced and, at the same time, a cause for joy as they are returned to their homeland."

Neil Curtis, senior curator of the Marischal Museum, said: "Not only are they once again going to be treated as ancestors, they will also now be studied and researched in ways that were not possible if they had stayed in Aberdeen."