Kenyan police have offered a reward of 1 million shillings ($7,700; £5,700) for information leading to the arrest of suspected serial killer Collins Jumaisi Khalusha, more than a year after he escaped from their custody.

Khalusha was the prime suspect in the murder of more than 40 women whose mutilated bodies were discovered in a disused quarry that became a dumpsite in the capital, Nairobi.

Shortly after his arrest, he escaped from custody, along with 12 others, after reportedly cutting through a wire mesh roof and scaling a perimeter wall.

This incident sparked outrage, and police are facing renewed backlash over their failure to hunt down Khalusha more than a year later.

Many Kenyans have questioned how he could have escaped on 20 August 2024 from what is regarded as one of the most secure police stations, located near the US embassy and the UN offices in the capital.

Khalid Hussein, an activist who has been following the case closely, told the BBC that the police were 'not serious' about solving the murders of women previously identified as aged between 18 and 30.

He alleged that some bodies were still inside the quarry pits, and 'rotting'.

Mr. Hussein believes the Directorate of Criminal Investigations (DCI) announced the reward in response to a documentary by Citizen TV about the police's inaction.

Police spokesman Michael Muchiri referred queries to the DCI, adding that it had previously addressed the complexities of the matter and was 'on track to resolving it.'

The DCI confirmed the reward would be given to 'anyone who provides credible information that will assist in the re-arrest of the suspect.'

Several policemen were arrested last year for allegedly aiding Khalusha's escape, though they were released on bail.

Khalusha had reportedly confessed to his crimes, but his lawyer later claimed that he was tortured to do so. At the time of Khalusha's arrest, DCI chief Mohamed Amin labeled him a psychopathic serial killer lacking respect for human life.

Interior Minister Kipchumba Murkomen described the escape as 'regrettable' and expressed hope for Khalusha's arrest.