An investigation has been launched after a buoy warning ships off the West Pier was cut from its moorings.
Brighton West Pier Trust suspects sabotage as the sea was calm when the bouy was cut loose early yesterday morning.
The buoy drifted west and was eventually collected at Shoreham Harbour.
It will be fixed back into position at the weekend but until then the charred pier will be unmarked.
Rachel Clark, general manager of the West Pier Trust, said she believed the mooring had been deliberately severed.
The buoy's absence caused a danger to shipping as a thick sea mist rolled in yesterday afternoon.
There were also fears it could have damaged the wrecked pier's foundations as it drifted past.
Planning permission was granted in February for the renovation of the pier but the project has been held up by legal challenges from the Palace Pier.
Since December there have been two arson attacks on the Grade I listed building. The concert hall has also collapsed.
English Heritage is reassessing whether restoration can be supported now so much of the pier has been destroyed.
Mrs Clark said: "The substructure is almost complete and it would be terrible if something went into it."
She said that, as with the arson attacks, releasing the buoy would have been a hazardous and difficult thing to do at night in deep water.
The incident has been reported both to Sussex Police and the Solent coastguard.
A coastguard spokesman said that if there were any problems in resecuring the buoy, a temporary marker could be put in place.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article