The Tourism Ministry has dismissed claims by an NGO that sand is being removed from Armier Bay to extend the beach's concrete area.
On Wednesday, Moviment Graffitti raised the alarm about loaders that they said were removing sand from the bay in Mellieħa.
The NGO claimed the "illegal works, which had not been issued a permit", had extensively damaged sand dunes that are rare and protected habitats.
They added that introducing concrete to parts of beaches such as Armier jeopardized the integrity of the entire beach.
According to Graffitti's sources, the works aim to accommodate lido owners at the same bay, the NGO said.
But a spokesperson said the works were part of "continuous and regulated" cleaning by the Cleansing and Maintenance Division.
The work was "regular and very normal", and did not require a permit, considering no algae was being removed.
"There are no plans for concrete to be laid under, or instead of the sand," he added.
Reacting to the NGO's post on Facebook, environmentalist and independent Żebbuġ councillor Steve Zammit Lupi said that sand dunes at the bay hosted protected sea daffodil plants.
"Just near them you can see the heavy machinery tyre tracks (some already trampled over) This plant and sand dune habitat are not only rare and localised, but also strictly protected."
Members of Moviment Graffitti insisted that cleaning of beaches was usually carried out between April and October.
They also questioned the need for such heavy machinery for the simple cleaning of sand, noting that the workers were not sensitive to the habitat.
Photos of the area show that vehicles had trampled on sand dunes, squashing protected plants, they added.