* Egypt court convicts activists over 2012 incident
* Probe opened into 2011 storming of domestic spy agency
* Interim head of state visits Coptic pope (Adds head of state visit to Coptic pope)
CAIRO, Jan 5 (Reuters) - Twelve Egyptian activists were given one-year suspended jail terms on Sunday in a case brought over an attack on the campaign headquarters of defeated presidential candidate Ahmed Shafik during the 2012 election.
The activists include siblings Alaa Abdel Fattah and Mona Seif, leading figures in the protest movement that triggered the 2011 uprising against autocrat Hosni Mubarak. The movement has been targeted in a widening crackdown by the army-backed authorities.
In a move that could open the way to more legal measures against prominent dissidents, the authorities opened an investigation into allegations that six activists took part in the storming of Egypt's domestic spying agency in 2011 - an important moment in the revolt against Mubarak's order.
It intensifies what activists see as an effort to discredit the secular protest movement as the government also pursues a crackdown on Islamist supporters of deposed president Mohamed Mursi ahead of elections later this year.
Sunday's verdict related to an attack on Shafik's campaign headquarters ahead of the presidential run-off against the Muslim Brotherhood's Mursi in the 2012 election.
The Cairo court convicted them of "displaying force", a charge they denied. "The ruling was political," Mona Seif told Reuters TV after the verdict was announced.
The case was brought earlier this year by a public prosecutor appointed by Mursi. At the time, activists said it was an attempt to intimidate the pro-democracy movement.
PRESIDENT MEETS POPE AHEAD OF CHRISTMAS
Since the military overthrew Mursi in July, the army-backed authorities have launched a crackdown that has mostly targeted Mursi's Islamist supporters but has recently widened to include members of the secular activist movement.
The government, which enjoys support among Egyptians eager to see a return to stability after three years of turmoil, has meanwhile pressed ahead with the political roadmap whose next step is a Jan. 14-15 referendum on a new constitution.
In symbolic outreach that could help shore up support for the roadmap among Egypt's Christians - about a tenth of the population - interim head of state Adly Mansour visited the head of the Coptic church ahead of the Jan. 7 Coptic Christmas.
The visit "reflected the state's appreciation for the great patriotic role they (Egypt's Copts) played in countering attempts to sow seeds of division among Egyptians," the presidency said in a statement.
Coptic Pope Tawadros had accused Mursi of neglecting his community and supported the Islamist's overthrow by army chief Abdel Fattah al-Sisi, widely seen as the man most likely to win a presidential vote expected in the coming months.
The new probe opened on Sunday relates to the storming by protesters of the headquarters of State Security, the domestic spying agency, several weeks after Mubarak's downfall. State Security was an important tool of political control in Mubarak's era. Critics likened it to East Germany's Stasi.
A judicial official said the public prosecutor had referred to the State Security prosecutor formal legal complaints against six activists.
The complaints were lodged after a privately-owned Egyptian satellite channel broadcast what it said were recordings of telephone conversations in which the activists discuss files found at State Security offices.
The complaints were filed by several people including lawyers who volunteered to defend Mubarak in the case brought against him for ordering the killing of protesters during the 2011 uprising.
The accused include Ahmed Douma and Mohamed Adel - two of three prominent activists sentenced on Dec. 22 to three years in prison each over for their role in recent protests.
That ruling drew condemnation from Western governments and local and international rights groups.
The government escalated its efforts to suppress Mursi's Muslim Brotherhood last month by declaring it a terrorist organisation, giving the authorities even wider scope to jail its supporters. (Reporting by Maggie Fick, Tom Perry and Reuters TV; Editing by Tom Perry, Rosalind Russell and Alister Doyle)