AFP - Iran will remove the fuel from the reactor of a Russian-built nuclear power plant in the southern city of Bushehr, a top official said on Saturday, citing technical advice from Moscow.

The plant, which has seen a roller-coaster ride since its construction began in the 1970s, was scheduled to generate electricity from April 9, and the latest development signals a likely delay in achieving that aim.

"Based on the recommendation of Russia, which is in charge of completing the Bushehr atomic power plant, the fuel inside the reactor core will be taken out for a while to conduct some experiments and technical work," Iran's envoy to the UN atomic watchdog, Ali Asghar Soltanieh, told the ISNA news agency.

"After the experiments, it will again be installed in the core of the reactor." He did not specify when the experiments would be completed.

Iran had started loading the fuel into the plant on August 21, which Moscow at that time said was the "physical launch" of the facility.

In January, Iran's former atomic chief Ali Akbar Salehi said the plant would be ready to generate electricity on April 9 after operations began on November 27.

The decision to remove the fuel, also supplied by Russia, is the latest development in the more than three-decade old history of the plant, which was first launched by the US-backed shah using contractors from German company Siemens.

But it was shelved when the shah was ousted in the Islamic revolution of 1979 and it lay unfinished through the 1980s as Iran battled internal opposition and a devastating eight-year war with Iraq.

It was revived in the late 1980s after current supreme leader Ali Khamenei succeeded revolutionary leader Ayatollah Ruhollah Khomeini.

In the early 1990s, Iran sought help for the project after being turned away by Siemens over nuclear proliferation concerns.

In 1994, Russia agreed to complete the plant and provide the fuel, with the supply deal committing Iran to returning the spent fuel.

A deal was finally signed in January 1995 after 18 months of negotiations and preliminary accords.

That was just the start of a spate of delays and setbacks, as the Russian contractor was repeatedly forced to postpone completion.

In 2007, Russian contractor Atomstroiexport even accused Iran of falling behind in its payments, further jeopardising the project's completion.

But finally on August 21 last year, Russian and Iranian engineers started loading the facility with the fuel, a move undertaken despite Moscow hardening its stance against Tehran's nuclear programme by voting for a new sanctions resolution at the UN Security Council.

The West, which suspects Iran's nuclear programme is cover for a weapons drive -- a charge vehemently denied by Tehran -- does not see Bushehr as posing any "proliferation risk," however.

Bushehr is a pressurised water reactor with a capacity to produce 1,000 megawatts of power.

It was constructed by more than 2,000 Russian engineers and workers living in a purpose-built village near the site.

Soltanieh said Iran wanted to put in place the "highest" safety standards at the plant.

"The complete responsibility for completing the Bushehr power plant in accordance with the highest safety standards is on Russia, and Iran has always emphasised and prioritised that the power plant must have the highest international safety standards," he said.