POLICE have launched anl investigation into allegations reporters from Fairfax's The Age newspaper illegally hacked into an ALP electoral database

Detectives from the VicPol's E-Crime Unit headed by John Manley executed a search warrant on the ALP's King St headquarters in Victoria on Thursday morning.

The warrant ordered Labor to surrender material relating to unauthorised access to the party's Eleczilla database during last year's state election and named reporters Royce Millar, Nick McKenzie and the newspaper's editor-in-chief Paul Ramadge and senior editor Mark Baker.

The search was triggered by a complaint from the Victorian Electoral Commissioner Steve Tully.

The database, which Labor is legally allowed to hold, contains personal details of millions of people, including names, addresses, telephone numbers and marital statuses as well as any confidential dealings between individuals and the party.

Among the high-profile people allegedly searched from inside The Age were radio broadcasters Neil Mitchell and Jon Faine, pollster Gary Morgan and Yarra councillor Stephen Jolly.

"The Age ran very hard against News of the World in England earlier in the year and, if through this criminal investigation they are caught with their pants down doing the same thing, they need to take a really hard look at themselves," a horrified Mr Jolly said.

A Victoria Police spokeswoman confirmed the matter was under investigation.

Three detectives from the E-Crime Unit arrived unannounced at the ALP's King St headquarters on Thursday.

In April, it was revealed the ALP had ordered an inquiry into the Eleczilla hacking.

The hacking allegedly took place over four days during last year's state election.

That month the newspaper published a report by Royce Millar and Nick McKenzie which said the newspaper had "gained access" to the ALP's database.

In June, The Age's senior editor Mark Baker said in a statement to the Sunday Herald Sun: "There is nothing improper, unethical or illegal in the actions of The Age. The conduct of our reporters . . . was a wholly legitimate exercise of journalism."