Keegan’s sister Nikki told the New Zealand Herald that it was “difficult to be happy with an investigation 10,000 miles away”, although she did not criticise the Kenyan police.

“We are working with our own sources to make sure the investigation is being carried out and is ongoing,” she said. “We may have to look into employing somebody.”

New Zealand born Keegan, 33, was found dead in a drainage ditch in Nairobi last month. He had been badly beaten, and his cameras and laptop were missing, although his wallet containing 3,848 shillings (£30) had not been stolen.

“It wasn’t a simple mugging,“Nikki told the New Zealand Herald. “There are so many suspicious questions into an ulterior motive. It doesn’t add up.”

Maasi land dispute

Shortly after Keegan’s death, police spokesman Eric Kiraithe told reporters that they were treating the incident as murder. “It does not appear to have been a robbery. If it was a robbery, the logical thing is that the robbers would have also taken his money.”

The manner of his death has led to speculation that the murder could be linked to a story Keegan was working on in neighbouring Tanzania concerning attacks on Maasai. The attacks were suspected to be linked to a land dispute between the Maasai and Massachusetts-based Thomson Safaris Company.

In the days before his death, Keegan had expressed concern to friends about his safety whilst covering the story, especially after he was approached by security contractors linked to Thomson Safaris. His family had begun telephoning him daily to check he was okay.

The Committee to Project Journalists has said that they are “deeply troubled” by Keegan’s death, and that they are carrying out their own investigation into the circumstances surrounding the death.