Detectives have determined no criminal offences were committed by Coalition MPs following a 10-month investigation sparked by the Deputy Premier referring more than a dozen names to police.

James Merlino asked Victoria Police to investigate 18 former and current Liberal and National Party MPs in July, claiming they misused taxpayer money and inappropriately used electorate office staff for political campaigning.

James Merlino made a complaint to Victoria Police about current and former Coalition MPs in July. Credit:AAP

The Fraud and Extortion Squad's investigation of Labor's complaint concluded on Thursday with no charges laid on any Coalition MPs.

"It has been determined no criminal offence occurred and as such, Victoria Police will take no further action," a police statement said.