The publisher of Britain's Sunday Mirror newspaper said Thursday that it is being investigated for alleged phone-hacking by former staff.

Trinity Mirror said police were examining whether its subsidiary MGN Limited, which publishes its five national newspapers, could be held criminally liable over allegations that Sunday Mirror journalists illegally accessed celebrities' voicemail messages.

"The group does not accept wrongdoing within its business and takes these allegations seriously," a Trinity Mirror spokesman said.

The police investigation is at a "very early stage", he added.

With a circulation of over one million, the celebrity-heavy Sunday Mirror is the weekly sister newspaper of the left-leaning Daily Mirror tabloid.

The Sunday Mirror's rival the News of the World, owned by Rupert Murdoch, was engulfed in 2011 by revelations that its journalists had hacked the phone of a murdered schoolgirl as well as hundreds of celebrities and public figures.

Murdoch was forced to close down the 168-year-old newspaper in July 2011 following a huge public outcry.

Dan Evans, a former journalist with both the Sunday Mirror and the News of the World, is among 16 people who have been charged over alleged phone-hacking.

Four Trinity Mirror journalists were arrested over suspected phone-hacking in March, including former Sunday Mirror editor Tina Weaver. All four were released on bail.

Trinity Mirror publishes more than a hundred regional titles in Britain and two Scottish newspapers as well as the Daily Mirror, Sunday Mirror and Sunday People.

More than a hundred people have been arrested under three police probes launched in the wake of the News of the World phone-hacking scandal.

The scandal also sparked a judicial inquiry into the ethics of the famously raucous British press, which recommended an overhaul of the newspapers' system of self-regulation.

...,/.,