A wealthy Canadian-Jordanian businessman, who was invited to the West Bank for an investment conference, has been arrested by Israel and held without legal advice, his lawyer said Monday.

According to Avi BarAm, Ibrahim Siyyam tried to cross from Jordan into the West Bank with a group of businessmen earlier this month but was detained by Israel's Shin Bet internal security agency and questioned without access to a lawyer.

"They claim he has ties to Hamas but it's not true," he told AFP.

"We deny all the charges."

Siyyam, who is of Palestinian origin, left the occupied territories decades ago, taking up citizenship in Canada and Jordan, the lawyer said.

Palestinian sources said Siyyam had been travelling with a group of wealthy businessmen to attend a top-level investment conference in the West Bank city of Ramallah which took place 12 days ago.

BarAm said his client was being held at a facility in Petah Tikva near Tel Aviv and that his remand in custody had been extended until May 25 at a court hearing at which he had no legal representation.

"We went to the Supreme Court over the fact that he wasn't given a lawyer but the court said it was a security matter," he said.

The Shin Bet did not respond to AFP's requests for comment on the case, which is being closely followed by diplomatic officials in Amman and Ottawa.

"Ibrahim Siyyam was arrested few days ago, and we are following up his case through our embassy in Tel Aviv and with his lawyer," Jordanian foreign ministry spokesman Sabah al-Rafei told AFP in Amman.

"So far nothing is clear. We are waiting to get details."

The Canadian foreign ministry confirmed one of its nationals had been detained in Israel but gave no further details, citing privacy concerns.

"Consular services are being provided to the Canadian citizen who has been detained in Israel," spokesman Nicolas Doire told AFP.

"To protect the privacy of the individual concerned, further details on this case cannot be released."