A bomb hoax which forced a major gay pride march to drop its new high profile route was deliberately designed to disrupt the event, Sussex Police said.
Specialist officers carried out a controlled explosion on the "suspect package", discovered on Brighton seafront shortly before the Brighton and Hove Pride parade was due to start.
Organisers had a planned a new "high profile" route for 2015 along the city's popular coastline but after a delay of more than an hour and a half were forced to resort to their former route.
Chief Superintendent Nev Kemp said: "We believe the item was placed there deliberately and made to look like a suspicious device to disrupt the parade. We have started a criminal investigation."
"We were concerned enough to call in the bomb disposal unit, who after making a further assessment, carried out a controlled explosion. The area had been cordoned off and there was no risk to the public.
"We want to apologise for any disruption this caused and thank the public and those taking part in the parade for their support and patience while we made the area safe and re-routed the parade. Their co-operation made dealing with this difficult incident easier.
"Despite the delay, we hope everyone will enjoy the Pride events across the city."
A police statement said the incident was being treated as a bomb hoax.