Family members said a prayer and walked to the steps of the parliament buildings, where they laid a black wreath with five white lilies.

Four of the lilies represented each of the remaining four of The Missing, and one was for the missing Lisa Dorrian.

It has been almost 20 years since she was last seen at a party at a caravan park in Ballyhalbert, County Down. Police believe she was murdered.

No one has ever been convicted and, despite many searches by land and sea, his body has never been found.

His father, John Dorrian, told BBC News NI that joining other families brought him some comfort.

“Coming here on this walk helps us meet other people who are in the same circumstances and we try to support each other,” he said.

“As a family, we feel sorry for the people who also have missing people because we know how they feel. I know these people have been missing since the ’70s. It must be terrible.”

Anne Morgan, whose brother Seamus Ruddy was one of the missing and whose remains were recovered in 2017, also attended the walk.

“We have discovered that being together has helped us be heard,” he said.

The walk is organized by Wave Trauma Centre, which has supported families of the missing since the mid-1990s.

The organisation’s chief executive, Dr Sandra Peake, said: “One of the evil aims of those behind missing people was to literally wipe every trace of them off the face of the earth as if they had never existed.

“The sheer inhumanity is shocking.

“Until all the missing are home, the families will not rest or remain silent.”