England have promised a major investigation into how their detailed plans for bowling in the fourth Ashes Test were leaked to Australian radio station ABC.

The tourists suffered another disappointing day with Australia fighting back to claim a 213-run lead on 372 for seven after Matthew Hayden and Andrew Symonds both scored centuries and forged a 279-run partnership.

But while they were struggling on the pitch, they suffered the further embarrassment of ABC Radio revealing the plans prepared by analyst Mark Garaway which detail the best ways for dismissing Australia's line-up.

The tourists are unclear whether the plans were taken from their dressing room or found elsewhere in the MCG, but England have launched an inquiry into the incident.

"There were several copies of the team bowling plans which are pinned up in the dressing room during the Test match and a copy of this plan has ended up in the possession of the media," admitted England spokesman Andrew Walpole.

"We are continuing our investigations into how it happened.

"We don't know at this stage whether the document was taken from the dressing room or from another part of the ground.

"We're talking to the ICC security manager and we're also talking to Cricket Australia, who are as disappointed about this as we are."