Musharraf, 74, ruled Pakistan from 1999 to 2008 as the head of a military dictatorship and now lives in Dubai in self-imposed exile The charges against him related to the imposition of extra-constitutional emergency measures in November 2007 which led to a number of superior court judges being placed under house arrest and the sacking of more than 100 judges.
Government law officer Salman Nadeem said: “Pervez Musharraf has been found guilty of Article 6 for violation of the constitution of Pakistan.”
The court’s full ruling was not available but it said in a summary it had analysed complaints, records, arguments and facts in the case and had reached a majority verdict, with two of the three judges giving the decision against Musharraf.
The charges stem from his imposition of a state of emergency in 2007, when he was facing growing opposition to his rule.
Musharraf seized power from prime minister Nawaz Sharif in a military coup in 1999 to bring an end to an economically disastrous administration.
He won a five-year term as president in a 2002 referendum but then went back on promises to quit as army chief until late 2007.
His popularity grew overseas when he joined the US “war on terror” in the wake of the September 11 attacks of 2001 and tried to tackle Taliban and al-Qaeda militants in Pakistan and also presiding over a period of record economic growth.
But his decision to back George W Bush was criticised by religious parties and ushered in years of Islamist violence in Pakistan as his regime began to lose support.
He tried to sack the chief justice in March 2007, sparking nationwide protests and months of turmoil that led to a state of emergency.
He was left isolated when allies suffered heavy losses in February 2008 elections held in the wake of the assassination of former prime minister Benazir Bhutto and finally resigned later that year in the face of impeachment proceedings by the new governing coalition.