The report published by State Comptroller Micha Lindenstrauss on Thursday alleged Galant lied to a court in a sworn affidavit saying he asked for permission to exceed building rights before building additional floor space in his home, The Jerusalem Post said.
Lindenstrauss found that Galant had requested a building permit retroactively after the structure had been built, the daily said.
Galant allegedly was also caught lying to the Israel Lands Authority in 2003 saying he had grown olive trees on the plot of land he requested for many years, but had started cultivating it in 2001, the paper said.
In August Defense Minister Ehud Barak appointed Galant as the next chief of staff to take over from outgoing Chief of Staff Lt. Gen. Gabi Ashkenazi who is due to leave the post next month.
The Green Party submitted a petition to the High Court of Justice asking it to disqualify Galant's appointment following an investigative report in Maariv that alleged he had illegally taken over public land near his home.
Lindenstrauss failed to recommend whether Galant should be disqualified, the newspaper said.
Attorney General Yehuda Weinstein will have to study the report and decide whether to defend Galant's appointment in the High Court against the Green Party's petition, the paper said.