Up to five American citizens have been arrested by Iraqi security forces in connection with the death of a US businessman in Baghdad's Green Zone.

If the men are charged, they will be the first Americans to be subject to the Iraqi judicial system since the Status of Forces agreement signed by the US and Iraqi governments. The Agreement, which removed US contractors' immunity from Iraqi legal proceedings, came into effect this year.

A Iraqi Ministry of the Interior official said that those charged were being held at an Iraqi police station inside the Green Zone, in connection with the murder of Jim Kitterman. Mr Kitterman, who owned a construction company and had worked in Iraq for six years, was found dead on May 22 this year.

According to reports, Mr Kitterman, who was 60 when he died, was found in his car in the Green Zone, with his throat slit, having been stabbed in the chest. The five arrested men have been detained as suspects, according to the spokesman, in connection with an investigation into the murder conducted jointly by US and Iraqi investigators, in which FBI officials were present at a search of the men's properties.

The US embassy confirmed that five men were being held, although later reports suggested only four men were detained, but would not comment further until after charges had been made. They have been visited in custody by officials.

Abdul Sattar Beraqdar, the spokesman for the Iraqi Supreme Judicial Court, told The Times that the men were being held while evidence was collected. If they are convicted, he said, they will be sentenced like any Iraqi. This could mean sentences in Iraqi prisons, or even the death penalty.

While neither US nor Iraqi officials would confirm the identity of the men, a company called Corporate Training Unlimited based in North Carolina is reported to have said that the men were employees and included a father and son named Donald Feeney, Jr and Donald Feeney III. A spokeswoman told of the, "mutual respect," the men had with Mr Kitterman, adding that, "the Feeneys are really devastated by his loss."

The Americans are the first arrested by Iraqi security forces since US troops relinquished control of the Green Zone on January 1, and Iraqi forces took over.

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