Polish investigators have asked Italian law enforcement services for the case files and information.
A district prosecutor's office in Warsaw is handling the case at the behest of Poland's Justice Minister and Prosecutor-General Zbigniew Ziobro.
According to Ziobro, there is a "legal basis" for the perpetrators to be tried according to Polish law.
Under Polish law, the prosecution service in Poland has authority to act when an offence against Polish citizens has been committed, "even if this happened abroad,” Ziobro told state television broadcaster TVP on Sunday.
"I therefore ordered an investigation to be launched immediately," he said.
It is the “duty of the state” to react whenever Polish citizens are at harm, Ziobro added. That is why Polish investigators will go to Italy to investigate the case, he told TVP.
The departure of the Polish investigators is scheduled for Tuesday, according to Ziobro.
The delegation will include a prosecutor, police officers and experts to assist Italian police in their own investigation.
Ziobro voiced hope that those behind the attack on the Polish couple will be quickly arrested and punished.
Illegal immigrants to blame?
Reports have suggested that the attackers are probably illegal immigrants from northern Africa.
Ziobro said this is “yet more proof” that countries where refugees have appeared on a larger scale are seeing a rise in crime.
According to Rimini police chief Maurizio Improta, the attackers were probably under the influence of drugs and alcohol.
Improta added that the attack was "inhumanly violent" and that he hopes the "attackers face a nightmare".
The group allegedly also attacked a transgendered Peruvian, whom they dumped at a roadside the same night.
The Polish pair, both aged 26, were on the beach late on Friday, their last night of vacation, when they were attacked, reports suggest.
Passers-by spotted the bloodied couple and called for help.
The man has been released from hospital while his wife remains, in shock and under psychological care.
Local authorities voice outrage
Local authorities have expressed outrage, calling the attack "brutal and bestial", Poland's PAP news agency reported.
Rimini police have opened a special probe into the attacks.
The foreign ministry in Warsaw has said that Polish consular services took immediate action to help the couple and their families. The Polish consul in Milan visited the raped woman in a hospital in Rimini on Sunday.
The victims of the attack have requested privacy, a spokesman for the Polish consulate has told PAP. (str/pk)
Source: IAR, PAP