By Andrew Gilligan BBC correspondent, Baghdad

Secrecy and surprise are essential to the weapons inspections but when the UN's nuclear experts, the IAEA, arrived for their first site visit yesterday it almost looked as if the Iraqis were expecting them.

The gates of the Tahadi plant were opened as soon as the inspectors drove up and the factory's management was waiting there to greet them.

UN sources in Baghdad said there could be other explanations for this but they confirmed that because of a lack of resources, no part of the inspectors' headquarters has yet been swept for Iraqi bugs.

Map-pointing

The building is believed to be infested with them.

One UN official told the BBC that when the nuclear team leader, Jacques Baute, briefed his inspectors on their first target, he refused to say its name out loud.

Instead, without speaking, he pointed it out to them on a map.

Other sensitive discussions have been held in the garden.

The UN wants more help with security, worried that its credibility could be damaged by leaks.