A year after a bomb ripped through Transport Malta’s Sa Maison offices, seriously injuring a traffic expert, the police still have no lead on who could have planted the handmade device.

Police remain with no suspects as to who dangled the bomb outside the office window of Konrad Pulè, the chief officer of land transport, while a meeting was taking place on December 2 last year, sources said.

It remains unclear whether Mr Pulé was targeted by the bomber but his office window was the only one located at the back of the authority’s premises on the side of the Sa Maison pine grove – from where the bomb was lowered.

He escaped unhurt but his colleague, traffic expert Major Peter Ripard, 75, lost a leg.

A wire and string found at the site pointed investigators to the conclusion that the bomber was onsite when the bomb was detonated at about 9.55 a.m.

He is believed to have lowered the device down a three-foot space, between the back of the authority’s building and an old bastion on the side of the Sa Maison pine grove.

The bomb is thought to have been held by the wire, while the string was used to detonate the explosive. The assailant then fled the scene through the grove as the attention of police and paramedics was directed to the area where the explosion wreaked havoc.

A few weeks after the explosion, Mr Pulé received a Christmas card with the words “I will not forget you” and in which a length of rope burnt at one end was enclosed.

Police carried out forensic tests on the card with the hope that results might shed light on the bomb case. But no lead emerged from the tests.

Investigators also examined the cases handled by Mr Pulè, to try and determine a possible motive. Mr Pulè did not have any possible suspects in mind.