Iraq\'s parliament speaker, who is on a visit to Washington, will query American officials about $17 billion in missing oil money, a lawmaker in Baghdad said on Wednesday. Osama al-Nujaifi, who left for Washington on Tuesday, will bring up the question of the missing billions, which have been under investigation for years, said Baha al-Araji, head of parliament\'s anti-graft committee. Last week, US officials acknowledged that $6.6 billion in Iraqi reconstruction funds had disappeared. Iraq says $17 billion is missing, and was stolen by corrupt US institutions. \"Nujaifi is visiting the United States to discuss several issues, including the missing funds,\" Araji said. \"We contacted the US forces in Iraq (about this issue) but we didn\'t receive an answer,\" he said, adding that Baghdad had approached the United Nations in Iraq to help trace the money. The cash was from the proceeds of Iraqi oil sales after the 2003 US-led invasion. It was placed in the Development Fund for Iraq (DFI), but went missing in 2004, when US envoy Paul Bremer\'s Coalition Provisional Authority (CPA) was governing Iraq and managing the fund. The integrity committee said it had sent a letter to the UN office in Baghdad, but a spokesperson for the United Nations Assistance Mission in Iraq (UNAMI) said no such document had been received. It was a 2003 UN Security Council resolution that authorised the transfer of the vanished Iraqi oil money from the US to Iraq. In the May 11 letter addressed to the UN in Iraq and seen by AFP, the integrity committee accused US institutions working under the CPA of stealing the money. \"The US institutions (occupation forces) working in Iraq committed a financial crime, stealing the money of the Iraqi people that was allocated for the development of Iraq,\" said the letter. \"The sum was $17 billion,\" it said. Iraqi government spokesman Ali Dabbagh said in a statement that the issue of the missing billions is being discussed at the highest levels in Baghdad. \"We call on US institutions linked to the issue to guarantee the rights of Iraq and hand over all accounts (from that period) to Iraqi auditors,\" Dabbagh said. The US embassy in Baghdad said it was working with the Iraqi government to account for the funds. \"The US and Iraqi governments share a commitment to transparency and accountability with regards to the history of the Development Fund for Iraq,\" said embassy spokesman David Ranz. \"Our two governments are working together, and with the Special Inspector General for Iraq Reconstruction, to account for all of the funds expended from DFI to benefit the Iraqi people.\" \"The issue is not about returning the money,\" said hardline MP Jawad al-Shehaili. \"It\'s about revealing that the US side did nothing for Iraq. It gave from the right hand and stole from the left,\" said Shehaili, who is a member of an alliance led by the radical and anti-American Shiite cleric Moqtada al-Sadr. Earlier this month, Iraqi authorities asked for visiting US congressman Dana Rohrabacher to leave the country after he called for Baghdad to repay part of the money Washington had spent on Iraq since the 2003 invasion.