Oil that spilled across the Sliema side of Marsamxett harbour on Tuesday was cleaned up by Wednesday afternoon, according to a spokesperson for the transport ministry.

However, floating barriers that prevented the oil from spreading further into the sea were kept in Marsamxett Bay in case more oil seeps beneath the Manoel Island Yacht Yard’s quays, the spokesperson said.

“Inspections were conducted on Wednesday evening and Thursday morning and no further pollution was detected,” the spokesperson said.

“We are not ruling out that small patches of oil may appear in the coming days.”

The spokesperson said the environmental health directorate was in charge of the clean-up.

It is up to the directorate to decide when the bathing area below Tigné Point will reopen, the spokesperson said.

Video footage and photos sent to Times of Malta on Tuesday showed oil appearing to wash into the sea from the Manoel Island Yacht Yard and stretching across to Tigné.

The Environment and Resources Authority (ERA) said on Wednesday morning it had confirmed that the spill consisted of “used oil” and that a clean-up had begun using specialised equipment.

Transport Minister Chris Bonett said on Wednesday that Transport Malta launched an investigation into the cause of the spill.

The probe will determine how similar incidents could be avoided and whether there was any negligence involved, he said.

Times of Malta understands that investigations pointed towards  Manoel Island Yacht Yard which admitted their yard was the source of the spill. 

"Workers seem to have accidentally spilt oil into the sea and failed to report the incident to the authority," TM sources said. 

The company will pay for the cost of the clean-up and fines that are still being established, they said. 

"The whole incident seems to have been an accident - TM recently inspected the yacht yard and found everything in order," the sources added.