Iran says certain members of the British Embassy staff in Tehran have been released after preliminary investigations but others will remain in custody, Press TV reported.
"The British Embassy played a crucial role in the recent (post-election) unrest both through its local staff and via media," IRNA quoted Intelligence Minister Gholam-Hossein Mohseni-Eje'i as saying on Sunday.
"We have photos and videos of certain local employees of the British Embassy, who collected news about the protests.," he added.
"The Embassy sent its local staff to rallies and inculcated ideas into the protestors and the society," said the minister.
Iranian security officials on Saturday arrested eight of the British Embassy's local staff members for 'inflaming post-election tensions' in the country.
Following the June 12 election, which saw President Mahmoud Ahmadinejad re-elected to a second four-year term, Iran became the scene of rallies with defeated candidates Mir-Hossein Mousavi and Mehdi Karroubi rejecting the result as fraudulent and demanding a re-run.
Iran has lashed out at what it calls foreign 'interference' in its internal affairs, saying the 'biased' attitude of European countries and their media incited the post-election unrest.
Following the detention of the British Embassy staff in Tehran, foreign ministers of the European Union warned that the 27-member bloc would meet any Iranian intimidation of European diplomatic staff in Tehran with a "strong and collective response".
Czech Foreign Minister Jan Kohout, who is currently the EU president, also urged Iran to immediately release the detained British Embassy staff members and the Greek journalist arrested in the country.
"The EU calls on Iran and its authorities to stop hostilities against EU member states as well as (the) EU's partner countries and their citizens and to release an EU journalist still in custody," said Kohout.
"The EU strongly denounces arbitrary arrests and repression against members of the civil society," he added.