Officers from the Environment Agency Wales have been patrolling beaches around Llanddulas looking for signs of pollution, after the MV Carrier cargo ship ran aground last week.
The Agency says 'natural factors' rather than pollution are thought to be behind reports of dead starfish being washed ashore, but is analysing water samples from area to confirm.
All of the fuel has now been pumped out of the craft, ahead of the break-up operation beginning tomorrow.
The owners of the HV Carrier, which ran aground on the north Wales coast last week, have said it is going to be demolished.
Work is continuing to remove the fuel on board the stricken cargo ship on the North Wales coast.
Commuters in Colwyn Bay have been dealing with long tailbacks after police closed the A55 to deal with the tanker that ran aground.