The Solai Dam case has been postponed by a month following a change of counsel in the defence side.
The court presided by Naivasha principal magistrate Joseph Karanja was told that the state counsel had not supplied the statements.
However, it emerged that the statements had already been supplied to the previous defence team handling the case.
In a joint statement for the defence, lawyer Tom Ojienda expressed his concern over failure by the prosecution to provide the statements as promised.
He noted that the incident occurred three months ago yet his client has not received any statement from the prosecution.
"We require two weeks to peruse the witness statements and another two weeks to prepare our defence. Unfortunately, this has not happened," he said.
Ojienda applied to the court to have the prosecution keep its word so that the case, which followed the death of 48 people after the dam collapsed, could kick off.
The magistrate also issued a warning to the prosecution to take the matter seriously and issue the statements before September 19 - the next hearing date.
He raised concerns with the prosecution's slowness in furnishing the defence with the documents despite getting ample time from the court.
In the case, nine suspects including Perry Manusukh - the owner of Patel Farm, are charged with 48 counts of manslaughter.
They also face two other charges of failing to prepare an environmental impact assessment report and neglect of duty.
The other eight suspects are Vinoj Jaya Kumar, Luka Kipyegen, Johnson Njuguna, Winnie Muthoni, Jacinta Were, Tomkin Odo Odhiambo, Willie Omondi, and Lynette Cheruiyot.
Last week, the High Court dismissed two applications from four of the suspects who had challenged their arrest and prosecutions in the case.
Judge Richard Mwongo noted that the due to public interest and the grave consequences that the collapse of the dam brought, the prosecution of the suspects should not be stopped.
"The matter should proceed and be determined expeditiously so that this issue can be laid to rest," he said in his ruling.