Unlike in killings, when people are forcibly disappeared, their relatives do not at least have the opportunity to pay their last respects, she points out.
She has told BBC Sandeshaya that therefore, abductions could not be treated as an issue of a particular community.
The secretariat has heard many tragic instances of enforced disappearances during its public sittings, Muttettuwegama said.
One woman lost her first husband in the late 1980s and the second a few years later, while most women described how they have had to endure abuse, insult and suffering in their quest for their missing relatives.
65,000 went missing
According to ex-president Chandrika Kumaratunga, around 65,000 persons had gone missing in the past few decades, as confirmed by commission reports into the JVP insurgency and the war with the LTTE.
However, the United Nations has details of around 15,000 missing persons, HR activsits say.
Sri Lanka is second only to Iraq in the number of disappearances, but if the actual figures are disclosed, Sri Lanka will top the table, they say.