Remains of the day: Millennium man's upper arm (above, right) is just one of the bones unearthed by Martin Pickford and Brigitte Senut (top). Credit: POPPERFOTO/EURELIOS

A year is a long time in Kenyan palaeoanthropology. In March 2000, Martin Pickford, a Kenyan-born researcher of British extraction, was arrested on charges of collecting without a research permit and spent five days in a Kenyan jail. Now he is the proud co-author of a paper1 describing Orrorin tugenensis, or the 'Millennium man' — a 6-million-year-old find that Pickford and his colleagues maintain is the oldest known human ancestor.

This claim has sparked intense debate — Orrorin's age is not in doubt, but some researchers question whether it is a member of the human lineage (see page 526). And the scientific controversy is only the beginning. No sooner had Pickford and his colleagues announced the find, at a press conference held in Nairobi last December, than Andrew Hill, chair of anthropology at Yale University in Connecticut, accused Pickford of encroaching upon his site in the Tugen Hills, part of Kenya's Baringo region. Pickford denies this, and alleges that Richard Leakey, former director-general of the National Museums of Kenya, and until recently head of the Kenyan civil service, incited last year's arrest. Pickford is now suing him for damages.

The controversy provides a glimpse of the bitter rivalries that can flare up between researchers competing for rights to study precious fossil sites, and how these rivalries can become intertwined with the politics of host countries. Although it is not an isolated case, the fact that the Tugen Hills row involves such a prominent figure as Leakey means that it will draw attention to this unseemly side of palaeoanthropological research.

The expedition that yielded the remains of Millennium man is a joint venture between Pickford's institution, the Collège de France in Paris, and the Community Museums of Kenya, a non-governmental organization established in 1997. The project is led by Pickford and Brigitte Senut of the Paris Museum of Natural History.

Permission to dig

Researchers wishing to carry out palaeontological research in Kenya must obtain a government permit, and be affiliated with an officially sanctioned Kenyan research organization. Traditionally, this role has been fulfilled by the National Museums. Some scientists allege that this has, over the decades, enabled the Leakey family to exercise reasonably tight control over who is allowed to conduct palaeoanthropological research in Kenya.

Louis Leakey in the 1930s established the dynasty with his wife Mary, also a renowned palaeoanthropologist. Their son Richard has continued the line with his wife Meave, who currently heads the National Museums' palaeontology division.

Pickford has long claimed to be a victim of this concentration of power. He worked in Kenya for his PhD in the 1970s, discovering a molar tooth2 that he argues comes from another specimen of Orrorin1. But Pickford's research in Kenya came to a halt in July 1985, when Richard Leakey barred him from the National Museums following allegations that Pickford had stolen field notes from the museums. Pickford claimed that he was falsely accused, and that he had been denied due process.

Leakey, who earlier this week resigned as head of the Kenyan civil service, stepped down as director-general of the National Museums in 1989. But Pickford did not return to Kenya until 1998, after finding an ally in Andrew Kiptoon, who was then minister for research and technology. In a letter dated 3 June 1998, Kiptoon invited Pickford to join with Eustace Gitonga, director of the Community Museums, in developing the archaeological and palaeontological potential of the Tugen Hills, adding that it would “not be difficult to obtain the necessary clearance, work permit, and other approvals”.

Bones of contention

From here on, the story becomes almost Kafkaesque. A research permit was granted to Pickford on 30 October 1998. But Hill points to a letter signed by J. E. Ekirapa for the permanent secretary of provincial administration, in the office of President Daniel arap Moi, dated 2 November 1998, cancelling the permit on the grounds that the application had not been properly submitted. It states: “Any research being undertaken on the strength of the cancelled permit is illegal and may lead to further legal proceedings.” This letter is also referred to in correspondence dated 21 April 1999 from the same office to the permanent secretary at the then Ministry of Home Affairs, National Heritage, Culture and Social Services, complaining that Pickford's excavations are “illegal and unauthorized”.

In March 2000, matters came to a head. Police and National Museums officials raided the Community Museums' Nairobi headquarters and at the same time intercepted Pickford in the field. He was charged with illegal excavation and imprisoned. But proceedings against Pickford came to an abrupt end in mid-April, when Kenya's Attorney-General directed the prosecution to drop the case.

Pickford and the Community Museums are now suing Leakey, the governors of the National Museums, and the Attorney-General, alleging unlawful arrest, false imprisonment and malicious harassment.

In court documents, Pickford claims the November 1998 letter was concocted to disrupt his work. He told Nature that he did not receive the letter until November 1999, and argues that it contains several irregularities. But Ekirapa asserts that the letter is genuine. Documents have been filed for the defence that deny all of the charges.

Pickford's dossier of evidence includes a letter dated 14 March 2000 from Leakey to George Abungu, the current director-general of the National Museums3. In this letter, Leakey notes that Pickford is collecting fossils and suggests “that you urgently get assistance from the Director of CID and that you send an officer plus someone from [the National Museums] to intercept Pickford. His possessions should be thoroughly searched and any fossils should be confiscated . . . A search should also be made of his premises in Nairobi.”

Abungu confirms that he received Leakey's letter, and that National Museums officials were present when Pickford was arrested. But when contacted by Nature, Abungu expressed sympathy for Pickford. “It appears he has a research permit,” says Abungu. “Pickford has definitely been a victim for a long time.” Abungu also supports the right of the Community Museums to provide affiliations for visiting researchers. “The laws have been too sympathetic to the National Museums,” he says.

Richard Leakey is not commenting on the row that has erupted over the fossil digs in the Baringo region of Kenya. Credit: AP

Leakey did not respond to requests to be interviewed for this article, and has not commented publicly on Pickford's allegations. But Hill is trading accusations with Pickford and his colleagues. In a short news story published in Science4 in December, he described Pickford's presence in the Tugen Hills as “highly irregular”. That article also recounted the story of the withdrawal of Pickford's permit, prompting angry responses from both Pickford5 and Gitonga6.

Irrespective of the dispute over the validity of Pickford's permit, Hill claims that the French team encroached upon a site in which the Baringo Paleontological Research Project, a joint venture between his Yale group and the National Museums, had operated since 1980. “We did a very carefully controlled excavation there, and Pickford came and dug trenches through the whole site,” he says.

Senut says that the French team made enquiries with local authorities to see if Hill was still working in the Tugen Hills before beginning the dig. “It appeared that there was no permit issued for the area,” she says. “It appeared also that Dr Hill had not put his feet in the area since 1993.” But Hill says he has visited the Tugen Hills every year except one over the past decade, and faxed copies of his permits and other supporting documents to Nature. His claims are supported by John Kingston, an anthropologist at Emory University in Atlanta, Georgia. “The last time I was there was in June 1999, and Andrew was there for two months,” he says.

Several palaeoanthropologists contacted by Nature declined to comment on such an incendiary row, which seems to be fuelled by deep personal animosities. Pickford certainly has antagonized his opponents: in 1995, he co-authored with Gitonga a book called Richard E. Leakey: Master of Deceit, which launched a ferocious attack on Leakey and several other leading palaeoanthropologists. Gitonga has also clashed with Leakey — who sacked him from his post of exhibits director at the National Museums.

“It is very difficult to know who is telling the truth,” says one US researcher, who asked to remain anonymous. But as the accusations continue to fly, the public image of palaeoanthropology could be the main loser.