Ebru Ozkan was arrested on Monday at Ben Gurion Airport in Tel Aviv while heading back to Turkey after having visited the city as part of a large tour group.
An Israeli court has ordered that a Turkish national arrested on terrorism-related charges be detained in custody for another week until her next court appearance.
Ebru Ozkan was arrested at Tel Aviv's Ben Gurion Airport earlier this week as she was about to board a plane to return home to Turkey. She will now remain in custody until June 21, when she is due to appear in court again.
"My client was referred today to a military court in the city of Petah Tikva near Tel Aviv on charges of threatening Israel's security and suspected affiliation with terrorist organisations," Ozkan's lawyer, Omar Khamayasa, told Anadolu Agency on Thursday.
Khamayasa said he had objected to a request by the military prosecutor to detain Ozkan for another 15 days and sought her release.
Khamayasa also objected to prosecution of a Turkish citizen in an Israeli military court, stating Ozkan's detention was "unlawful and arbitrary."
The Turkish embassy in Tel Aviv said it was closely monitoring the case.
Elif Ozkan told Anadolu Agency that her sister stands accused of being a security threat and member of a terrorist organisation.
She was adamant that Israeli authorities had no evidence or documents that implicated her sister in any wrongdoing.
Melek Unal, a friend, who had travelled with Ozkan to Jerusalem, said that they had visited Jerusalem as part of a large tour group of about 40 people.
Ozkan said: “We could not contact my sister in any way. We could not even make a phone call. Even her lawyer could not speak to her, even though he was at court. The lawyer will meet with her on Monday.”
“It is unfair and unlawful for a woman to be detained in this way. It's against human rights. Israel is approaching the issue politically. It's an arbitrary detention,” she added.