Paul Mackenzie, the Kenyan preacher at the centre of a doomsday cult that led to the deaths of more than 400 people, was found guilty on Friday, but not of their killings.

The senior resident magistrate in the town of Malindi, Olga Onalo, instead found Mackenzie guilty of operating a TV studio and distributing films without a licence from the Kenya Film Classification Board.

The preacher has been in police custody for more than six months now since he was arrested in April, following the discovery of hundreds of bodies in mass graves in a forested area across his 800-acre property in the coastal county of Kilifi.

Prosecutors say Mackenzie ordered his congregants to starve to death in order to meet Jesus.

However, he has not been formally charged over the deaths, despite being arraigned in court on numerous occasions since his arrest.

The Office of the Director of Public Prosecutions tweeted on Friday that Mackenzie is the "prime suspect."

And on Friday he was acquitted of additional charges of influencing children to not attend school and using radical preaching to incite Christians against Hindus, Buddhists and Muslims.

He will be sentenced for the film-related offences on Dec. 1 and could face up to five years in prison.

On Thursday, prosecutors applied to have Mackenzie held in custody for six more months to allow police to complete their investigations which include the search for dozens of people still missing.

Since his arrest, there have been growing calls for the government to regulate churches in Kenya.