Egyptian police arrested a 25-year-old Israeli man on Friday and have detained him since, his family said Monday.

It remained unclear as of Monday afternoon under what circumstances Andre Pshenichnikov of the Tel Aviv suburb of Bat Yam was arrested, nor was it apparent why he had traveled to Egypt.

Pshenichnikov’s mother told Ynet that after several days of not hearing from him, he called to inform her that he was at an Egyptian police station.

The Foreign Ministry confirmed that an Israeli was under arrest in Egypt, but could not confirm his identity, and said the matter was under investigation. It said it was communicating with Egyptian authorities, who were cooperative.

The Egyptian Embassy in Israel was not available for comment.

A man of the same name caused a stir earlier this year when he declared that he wished to renounce his Israeli citizenship and adopt Palestinian citizenship.

“I hate Zionism,” he told the Associated Press in June. “I want to be part of the Palestinian resistance.”

In October 2011, American-Israeli Ilan Grapel was released from Egyptian prison in exchange for 25 Egyptians in Israeli jails, after being incarcerated for five months on espionage charges. Grapel was working for an Egyptian NGO that aids refugees from Iraq and Sudan.