Unnamed senior figures within Victorian Opposition Leader Daniel Andrews’ office and the Labor party were involved in stealing a Fairfax journalist’s tape recorder and leaking details of a private conversation with former Liberal premier Ted Baillieu, The Age newspaper alleges.

The ALP has rejected the allegations.

On the tape, Mr Baillieu is heard referring to independent MP Geoff Shaw, upper house Liberal MP Bernie Finn and his “crazy mates”, and federal government minister Kevin Andrews in a taped recording between himself and a journalist from The Age.

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The Age newspaper says the tape recorder was handed in to lost property by security staff at the Labor party state conference in Melbourne in May but was listened to by “one of the top officials in Victorian Labor ranks”.

That person did not release the tape’s contents on legal advice but they were released against that person’s wishes the following month by email to hundreds of Liberal Party members by a person using a false name and purporting to be a fellow Liberal.

“It is understood that copies of the taped conversation were made by a senior Labor official and scrutinised by others in the party’s organisational wing, as well as senior strategists in Mr Andrews’ office,” the newspaper said.

“The group is believed to have debated whether the recording could be released publicly to fuel tensions in the Liberal Party ahead of the November 29 state election.”

The Age questioned Mr Andrews and a series of figures within his office and the Labor party about the tapes.

In response, State secretary Noah Carroll issued a brief statement.

“The Victorian ALP categorically rejects any suggestion that it was involved in the theft of any Dictaphone or the distribution of the contents of any Dictaphone,” he said.

“As this matter is currently being investigated, we shall not be making any further public comment.

“I wish to advise you that this is the collective response of all of the individuals that you have sent similar questions to this afternoon on this matter.”