Iran says it has detained a number of ‘nuclear spies’ in connection with the Stuxnet malware attacks on its nuclear programme computer systems last week.

Who has been arrested and on what evidence has not yet been explained, but the country’s Intelligence Minister, Heidar Moslehi, adopted a triumphant tone in reported comments made to the Iranian Mehr News agency and domestic TV sources.

“All of the destructive activities perpetrated by the oppressors in cyberspace will fast be discovered, and ways to counter them will be implemented,” Moslehi was quoted as saying.

"We are always facing destructive activities by these [spy] services, and, of course, we have arrested a number of nuclear spies to block the enemy's destructive moves," he added.

The malware-worm is assumed to have been designed to attack Iran’s systems specifically although this is difficult to confirm as not all the systems affected by Stuxnet were in Iran. The worm has also been active for some time.

Particular suspicion has fallen on Israel, which has the security expertise and motivation to attack Iran’s nuclear programme but, again, as yet such allegations are little more than hearsay.

The country has said it is still battling Stuxnet, which is believed to have infected tens of thousands of PCs in the country.

Symantec has posted a detailed analysis of how the worm works. What is clear is that removing it will take time as it can also inject blocks of code into control systems used in nuclear engineering software. The company has speculated that the malware looks like the work of a team of programmers.