ZAGREB • Luka Modric could face five years in prison after Croatia's state attorney opened investigations into whether the Real Madrid midfielder gave false testimony at the trial of Dinamo Zagreb's powerful former boss Zdravko Mamic.

Modric testified last week at the trial of a tax official and three former senior officials from the Croatian football club.

The state attorney's office in the eastern city of Osijek, which is running the investigation of the false testimony, did not name Modric, as is standard procedure in Croatia.

But the state attorney's office on Monday referred to a Croatian born in 1985 who testified last week, a description that fits only Modric.

Local media, including state radio and television, identified Modric as the investigation's target.

The 31-year-old Croatia international could not immediately be reached for comment.

He testified as a witness at the trial of tax and Dinamo officials on charges that they avoided paying HRK12.2 million (S$2.5 million) in taxes and diverted HRK116 million from the club, anti-corruption police said.

"The witness falsely said that on July 10, 2004, the date when he signed his first professional contract, he also signed an annex on the basis of which he had acquired a right to a 50-50 share in transfer fees," the Croatian state attorney said in a statement.

The state attorney also said Modric falsely claimed that he had signed such an annex every time he extended his contract.

Two years ago, Modric testified to anti-corruption investigators that he had signed an annex to his contract at a later point, when he had already joined a foreign club, according to the state attorney.

He moved to Tottenham from Dinamo Zagreb in 2008 before joining Real Madrid in 2012.

False testimony is punishable with up to five years in jail.

Modric was visibly uncomfortable, and at times appeared confused last Tuesday when he gave evidence at the tribunal.

All three former Dinamo officials, including former coach Zoran Mamic and the club's former executive and current senior official of the Croatian Football Federation, Damir Vrbanovic, deny the charges that have been filed against them.

REUTERS, AGENCE FRANCE-PRESSE