Suspected of tax evasion and bribery, Mamic and five others were arrested in 2015 following accusations of embezzlement through commissions taken from player sales, one of which was the sale of Modric from Dinamo to Tottenham in 2008.
Modric was therefore chosen as a key witness in the trial, but now the 32-year-old maestro stands accused of giving false testimony at a hearing last week after seemingly making a U-turn on the original statement he made to authorities in 2015.
A DORH statement read: "State Attorney's Office in Osijek opened the investigation against Croatian citizen (1985) due to the existence of reasonable doubt that when giving testimony before the County Court in Osijek committed a crime against justice by giving false testimony under Article 305, paragraph 1 of the Criminal Code / 11. (6th 19th 2017)."
The issue centres on a clause in Modric's old contract with Dinamo in which it was agreed that a portion of any transfer fee would be split 50/50 between the player and the club. There is, however, a problem with when exactly that was inserted into the contract, with suggestions it was added and then subsequently backdated after Modric had already been sold.
That version of events is what the 32-year-old is believed to have originally told authorities, but he has now given different testimony. The DOHR statement explains that there is 'reasonable doubt' that Modric falsely testified on 13th June 2017 after being warned it was an offence to do so.
Perjury can carry a jail term of anything from six months to five years in Croatia.