Kilifi county assembly Committee on General Oversight shall summon IFMIS and Central Bank of Kenya officials as well as bank managers for probe on the loss of Sh1.8 billion.
Speaker Jimmy Kahindi said there was a possibility that the agencies colluded with county officials to steal funds from the county's coffers.
This was after the assembly interrogated 10 county officials who were suspended after the scandal was unearthed.
Kahindi however said they still believe only Sh 51 million was stolen since there is no evidence to back claims that the county lost Sh1.8 billion instead.
"We have records showing that Sh51 million was withdrawn and paid to bank accounts of five companies. This is what is under investigation," he said.
The Speaker confirmed that one of the suspended officers claimed there is a possibility that the county could have lost about Sh1.8 billion.
"The official did not give any documentary evidence to support the allegations," Kahindi said, further asking leaders not too politicise the matter at the height of the investigation.
On Tuesday, the officials, who were suspended after it emerged that their passwords were used to withdraw the monies, refused to testify on camera citing fears for their security.
It is believed that the evidence they gave touched on some of their seniors who were also part of the scandal. Journalists and members of the public were locked out of the grilling.
Last week, chief finance officer Ben Kai, senior accountant (Health) Jacob Konde and county secretary Owen Baya told the assembly that an investigative report showed that Sh51,209,775 was missing.
No suspect has been arrested despite the fact that names have been mentioned in regard to the scandal.
The speaker said they will demand for IP addresses from the Ifmis department to be used in tracing the transactions.
The money was fraudulently wired to Makegra Supplies, Zohali Supplies, Kilingi Investment, Leadership Edge Associates and Daima One Enterprises.
Lenox Mwadzoya (Inspector, Roads), Paul Mwazo (Deputy Director, Treasury), John Kalume (senior accountant, finance) and Josephine Muramba (Principal accountant, education) were among those interrogated by the committee.
Lilian Hariri (health clerical officer), Vivian Sidi Nzai (water accountant), and Johnson Nyamawi Gambi (senior accountant, finance), health chief officer Timothy Malingi and Dickson Tembo (Clerical officer, agriculture) and Senior health accountant Jacob Konde were also probed.
The Central Bank of Kenya, IFMIS department, EACC, CID and Anti-Banking Fraud Unit of the Central Bank of Kenya have began investigation into the scandal.
Governor Amason Kingi told the investigative agencies to move with speed so that the perpetrators of the fraudulent transactions are brought to book.
The governor wondered why the Ethics and Anti-corruption commission and the Anti-Banking fraud unit have not arrested anybody yet there is already enough evidence.
"It is now over a month since the matter was reported. It raises suspicion why no one has been arrested in connection to the heist," Kingi said.