The death toll from a Kenyan starvation cult crossed 300 on Tuesday after authorities exhumed more bodies in a forest, in one of the worst cult-related tragedies in recent history.

Authorities say the dead were members of the Good News International Church, led by Paul Mackenzie, who is accused of ordering his followers to starve themselves and their children to death so they could go to heaven before the end of the world.

A total of 303 people have now died after 19 bodies were exhumed from mass graves in Shakahola forest in the country's southeast. More than 600 people are still reported missing, regional official Rhoda Onyancha said.

Investigators last week expanded their search to cover a wider area in the region to try to account for more victims.

Around 65 rescued followers of the self-styled pastor were charged with attempted suicide on Monday after they refused to eat between June 6 and June 10 during their stay at a rescue center, local media reported.

Interior Minister Kithure Kindiki expressed concern last month that some of Mackenzie's rescued followers were refusing food. One of them had died, he said at the time.

Mackenzie handed himself over to police in April and was denied bail last month. He has not yet been required to enter a plea.

He was arrested on suspicion of the murder of two children by starvation and suffocation earlier this year but was subsequently freed.

Relatives of his followers say he then returned to the forest and moved forward his predicted end of the world date from August to April 15.