The Spanish high court has asked to be informed if the Israeli prime minister should arrive in Spain.
The court earlier this year archived an investigation into an incident in 2010 which left ten dead after an aid flotilla bound for Gaza was raided by Israeli commandos.
But the court has indicated that it possibly could re-open the case.
Commandos landed on the largest flotilla vessel, the Turkish-owned Mavi Marmara, by descending on ropes from helicopters. Clashes broke out immediately and the Israeli commandos opened fire.
Ten Turkish volunteers died as a result and dozens were wounded.
The court was obliged to shelve the case under a new law which prohibited the use of universal jurisdiction on international cases unless there is a connection to Spain, such as a Spanish victim or perpetrator.
Spanish activists had been on board the raided ship.
PM Netanyahu (pictured) and several of his ministers had been accused of crimes against humanity as part of the Spanish court investigation.
The court said in a written ruling released on Wednesday that the case had only been provisionally shelved, but could potentially be reopened if the court had the means to move forward under Spanish jurisdiction, including if some of the accused were in Spain.
