AMMAN (Reuters) -Israel has detained a Jordanian lawmaker on suspicion of smuggling arms and gold into the West Bank and Amman is working to secure his release, the kingdom's foreign ministry said on Sunday.

Imad al Adwan, a member of parliament who had crossed a main border crossing along the Jordan River earlier on Sunday by car, was being held and interrogated by Israeli authorities, Sinan al Majali, a Jordanian foreign ministry spokesperson said in a statement to state media. Reuters could not immediately identify his lawyer.

"The ministry in coordination with the relevant agencies in the kingdom was efforting to get details of the case and resolve it as speedily as possible," Majali said.

A spokesperson for Israel's foreign ministry declined to comment on reports of the arrest.

Prominent Jordanian lawmaker Khalil Atiya, known for his vocal opposition to Israel and who has led campaigns to repeal the country's peace treaty with Israel, said the government would be held responsible if it failed to act quickly.

"There should be no room left for the enemy to harm the dignity of Jordanians by detaining and jailing a member of the parliament," Atiya said.

Israel enjoys close security ties with Jordan, the Arab neighbour it shares its longest stretch of border with, but political relations have soured in recent years over Israel's stance on the right of Palestinians to a state.

Many of the kingdom's citizens are of Palestinian origin.

(Reporting by Suleiman Al-Khalidi, additional reporting by Ari Rabinovitch in Jerusalem, editing by Deepa Babington)