The assembly’s deputy speaker Roy Samo told Nation that Mr Oloo was arrested following a directive from the EACC.
Mombasa EACC boss Japhet Baithalu said Mr Oloo would be taken to Nairobi.
Police in Mombasa are holding Kisumu County Speaker George Onyango Oloo over Sh2.5 billion LBDA mall scandal.
Mr Oloo, who was being sought by Ethics and Anti-Corruption Commission (EACC), was put in police custody after presenting himself to Central Police Station at around 2pm Saturday.
The speaker surrendered to the police in Mombasa in the company of several members of the Kisumu County Assembly.
The assembly’s deputy speaker Roy Samo told Nation that Mr Oloo was locked up following a directive from the anti-graft body.
“We had come to present him so that people can confirm that the speaker was not running from anyone. The officers have appreciated him for presenting himself,” said Mr Samo.
Mombasa EACC boss Japhet Baithalu said Mr Oloo would be taken to Nairobi. “He is at Central Police Station,” Mr Baithalu told Nation on phone.