Double Olympic marathon champion Eliud Kipchoge on Friday paid tribute to Kelvin Kiptum after the world record-holder died last month when his car crashed into a tree.

Kipchoge is preparing to compete in Sunday's Tokyo Marathon in his first race since Kenyan compatriot Kiptum was killed on February 11 at the age of 24.

Kiptum died just months after beating Kipchoge's world record and the two were expected to face off for the first time at this year's Paris Olympics.

The 39-year-old Kipchoge said it was unfortunate that Kiptum died, noting that his career was in high spirits and was running on a high level.

Although Kiptum only competed in three marathons, he won all of them and posted three of the seven fastest times in history.

The father of two was driving in the Rift Valley, the heartland of Kenyan distance running, when his car careered off the road.

Police said Kiptum and his Rwandan coach Gervais Hakizimana were killed on the spot while a woman passenger was injured.