Vladimir Grezdilov, general director of the Mir company, which has a contract to build a mobile tower for Soyuz-ST carrier rockets, said the company was the victim of ongoing raids from a private security firm.
He said that the raids may prevent it from implementing the contract.
He said that in January the firm had seized 24 Mir buildings, including over 110 engineering tools, with most of the company personnel quitting as a result.
The director said the company was running behind schedule, having completed only 40% of the contracted work so far.
"The raids are continuing. Today 30 people from a private security firm broke onto the territory of the factory...taking away property," he said.
He also added that local police had taken no action against the group.
The first launch of a Soyuz carrier rocket from the Kourou space center is planned for 2009.
The Kourou launch site is intended mainly for the launch of geostationary satellites. Its proximity to the equator will enable the Soyuz-ST to put into orbit heavier satellites than from Baikonur in Kazakhstan and Plesetsk in northern Russia.
Under a contract signed in June with the French satellite launch firm Arianespace, the Soyuz will have a separate launch pad near Sinnamari, a village 10 kilometers (six miles) north of the site used for the Ariane-5, the main European-made booster.
Launches of Soyuz spacecraft are the key part of the Russian-French program of cooperation in space exploration.
