The Labour Party yesterday said it was disgraceful that the source of the black dust found in the south had not yet been established.

After The Sunday Times reported that the analysis carried out had not yet yielded results, Labour Party spokesman Leo Brincat said such delays could prove harmful to health.

He pointed out that the opposition had flagged the problem on August 1 and several mayors had raised the alarm even before that. However, the government still said more samples were being collected for analysis.

"One expects that in this day and age when state-of-the-art equipment must exist, such analysis could easily be done. Moreover... should the need arise, tests could be made abroad," he said.

Residents in Sta Luċija, Fgura, Paola, Tarxien, Żabbar and Żejtun this summer complained that black dust was covering their roofs and cars but the Malta Environment and Planning Authority said the analysis process was proving difficult since the dust seemed to have diminished since.

It said it was now working with the Fgura local council to collect further samples.

Meanwhile, Enemalta has denied accusations that the black dust was being emitted by the Marsa power station.