Three more suspects have been arrested by the Flying Squad over the hacking scandal.
Two suspects are employees of the Kenya Revenue Authority stationed at the Information Technology Department.
A third suspect was an employee of Kenya Commercial Bank until a while ago when he was fired.
The case, according to a detective privy to the investigation, is already facing tough hurdles because commercial banks involved are unwilling to co-operate.
The Nation learnt that the banks fear losing customer confidence, which could lead to panic withdraws of deposits.
So far nine suspects have been charged in court at the Jomo Kenyatta International Airport on Wednesday and Thursday.
Another suspect, also from KRA, was being tracked and was expected to be arrested later in the night.
The banks fear the revelations will make them look like they are vulnerable to cyberattacks.
Also, they are unwilling to let detectives access their systems and are categorical that their machines will not be carted away by detectives.
This could deny the police much needed exhibits to build a water-tight case in court.
There is also an intricate intelligence network that unearthed the scandal, which must remain anonymous and thus cannot be revealed in court.
A detective said the case might have very weak grounds and could be easily challenged in court.
Police need unlimited access to technology tools at the banks to proceed with the case, according to an investigator.
However, it emerged that some of those arrested might be turned into prosecution witnesses.
The matter is being investigated by the Flying Squad, Cyber-Crime Unit, the Special Crime Prevention Unit and the Anti-Narcotics Unit.
Meanwhile, a laptop belonging to one of the suspects arrested today, Ms Lucy Jemiat, a KRA employee, has also been confiscated.
Ms Jemiat has been linked to a cartel of present and former employees of KRA who were arrested on Tuesday and Wednesday.
Police have requested the court to allow them to detain her for 20 days as they conduct investigations.
Detectives also discovered that the suspects had connected a KRA server located on the third floor of Times Tower to the Afya House office of one of the former employees, known simply as ‘Riaga’.
Detectives also interrogated several KRA and bank employees.
On Wednesday, it emerged that the group had also targeted the National Transport and Safety Authority (NTSA) system.
National Police Service Spokesperson George Kinoti said more people, including bank employees and foreigners, could be arrested.
Sixteen people, among them a former police officer attached to the Directorate of Criminal Investigations, two Americans and three KRA employees, were arrested on Wednesday.
A laptop hidden in the KRA network chambers and connected to one of the ports was also found.
Mr Kinoti said it took long to unravel the racket because the crime was silent and could only be detected through information from the affected institutions.