By Syed Shoaib Hasan
BBC News, Islamabad
A Pakistan human rights organisation has accused the government of continuing to detain hundreds of citizens without trial.
Mr Khawaja has been a thorn in the side of the Pakistan government
Domestic and international rights groups have repeatedly called for the release of those detained.
The Pakistani government had long denied holding them.
But a judicial inquiry led by the country's now dismissed top judge Iftikhar Chaudhry managed to get dozens freed from custody.
Mr Chaudhry's efforts came to an end in November 2007 when President Musharraf sacked several top judges including Mr Chaudhry, accusing them of "interfering" in the use of executive powers.
"In all, 521 people have been kidnapped since 2001, 98 of whom later returned home," Khalid Khawaja, head of the Defence of Human Rights organisation told the BBC.
"There are 422 cases where the missing people have still to be recovered."
Many have lost confidence in ever seeing their loved ones again
"The most recent are two young men, Abdullah and Shaban, who were kidnapped from their homes in Faisalabad on 30 January.
"They were taken away by security personnel without charge, and the local police refuse to register their families' complaints."
Mr Khawaja and his organisation have pioneered the fight to locate the missing people of Pakistan.
Most of the people are said to be suspects or related to people involved in alleged terrorist activities.
"The entire movement against Musharraf was launched to get these people free, but now everybody has forgotten about them," Mr Khawaja contended.
He said a majority of those classified as missing had been tortured in custody.
Mr Khawaja himself was imprisoned for several months last year, including a period when the government declared it had no knowledge of his whereabouts.
He remains a controversial figure, having acknowledged ties with the Taleban and al-Qaeda leaders in the past.
He did not seem optimistic about the recent elections changing matters.
"All the parties who have won the election have more or less tacitly agreed to protect the interests of the Americans," he said.
Mr Khawaja is demanding that the UN holds an inquiry into the missing.