Samuel Dalli walked out of his Żurrieq home on January 18 at 2.45 p.m., telling his parents he was going to meet a friend. He only had his mobile phone in hand, leaving his keys, wallet, identity card and passport behind. Nobody has seen him since.

His father reported Samuel missing on the day of his mysterious disappearance, but the investigation has so far been unable to establish what happened.

Samuel, due to turn 35 on July 6, had been unwell and was on sick leave. His car, parked outside his home, had not been touched for a week, so his father asked him to start it for a few minutes.

As he speaks, Carmelo, his father, stares into thin air and says he can vividly remember the smile on his son's face when he bid his parents goodbye in the kitchen.

"It never crossed our mind that we would not see him again. Since Samuel hadn't been out for a week, I even asked him whether he would like to go for a walk with me, to distract him," says Carmelo. "But he refused, saying he was supposed to meet someone."

His bank accounts were left untouched. Carmelo says his son could have walked, caught a bus, met a friend or even hitched a ride with a stranger.

"The police were extremely helpful. They searched our home for clues that could perhaps lead them to Samuel, but to no avail." Civil Protection officials also carried out various search patrols in the hope of finding him.

There will certainly be no cause for celebration at the Dalli home today as the world marks Father's Day.

Carmelo says: "We live in hope, whatever the outcome. My son is still missing and I will not rest until I find him. He could be anywhere. That fateful weekend in January has turned our lives upside down and we are living a nightmare."

A Maths teacher by profession, shortly before his disappearance Samuel changed job to a clerical position, still within the Education Department.

"He was a good-natured person. Having seen his photo in the papers after he went missing, former students have come up to us saying 'Oh, he used to teach me Maths', or 'Look, that's our Maths teacher!'"

Samuel also did a lot of charity work. He loved going to Id-Dar tal-Kleru in St Venera to help out and attended prayer groups regularly. "He was a good boy", says Carmelo.

Carmelo calls Samuel's mobile number every now and then. But all he hears is a recorded voice at the other end, saying the number no longer exists. Hope has been fading away.

"But I will always look for my son. He could be lying under a rubble wall or a carob tree in a forlorn place.

"Even though Malta is tiny, searching everywhere is not easy. But Samuel just has to be somewhere."

Samuel is almost 1.8 metres tall and has short brown hair. On the day he went missing he wore jeans and a round-neck navy blue sweater and white trainers.

Anyone with any information is requested to call 119 in confidence.