Eight people among them Treasury Cabinet Secretary Henry Rotich have been arrested on fraud and corruption charges over the multibillion-shilling Arror and Kimwarer dams projects in Elgeyo-Marakwet.
Treasury's Principal Secretary Kamau Thugge joined his boss at the DCI headquarters when he presented himself soon after the arrest orders were made by the Director of Public Prosecutions Noordin Haji.
Others held at the Directorate of Criminal Investigations offices along Kiambu Road are East African Community PS Susan Jemtai Koech and the National Environment Management Authority (Nema) director-general Prof Geoffrey Mwangi Wahungu.
Mr Wahungu was arrested in Tharaka-Nithi County, eastern Kenya, and taken to the DCI headquarters.
Tharaka-Nithi County criminal investigations boss Ms Betty Chepngeno said Prof Wahungu was arrested at his home in Rukindu Estate in Chuka.
"Yes, we have arrested the Nema Director General and we are already on our way to Nairobi DCI headquarters," said Ms Chepngeno confirmed on phone.
In North Rift, Uasin Gishu County, detectives raided the Kerio Valley Development Authority (KVDA) headquarters in Eldoret and arrested the acting Managing Director Francis Kipkech, who is a member of the tender committee.
Also arrested are KVDA tender committee members Patrick Kiptoo and David Juma Onyango, and Charity Muui, a clerk for the Ad hoc Technical and Evaluation Committee.
Presence of the detectives at KVDA shortly after Mr Haji made the arrest orders caused a stir and panic among staff.
Some of the suspects, however, escaped the police dragnet during the 11am raid.
The detectives are now hunting for 13 KVDA staff implicated in the dams scandal that saw taxpayers lose Sh21 billion paid out to a bankrupt Italian firm for the projects which never took off.
Those arrested were taken to the Eldoret Central Police Station awaiting to be transferred to Nairobi for arraignment.
The suspects face eight charges of economic crimes.
The Sh35 billion Arror dam in Marakwet West and Sh28 billion Kimwarer dam in Keiyo South were expected to serve more than 50,000 people.
The directors of CMC di Ravenna and Itenera of Italy that was awarded the tenders are among suspects to be arrested over the scam for allegedly bribing senior government officials.
- Reporting by Vincent Achuka, Alex Njeru, Barnabas Bii.