Police were today still questioning two men after a man was killed and another seriously injured in a crash between two speedboats.

The men, from the Brighton area, were arrested following the collision half a mile off the Palace Pier, Brighton, at 6.50pm yesterday.

They were believed to be the drivers of the 25ft powerboats. Both were being held at Brighton police station.

Detectives leading the investigation appealed for witnesses to come forward.

Early reports from lifeboat officials said one of the boats scythed into the side of the other vessel, hurling one man into the sea.

Lifeboats from Brighton and Shoreham joined a flotilla of fishing boats and other pleasure craft in the search for the missing man.

The 46-year-old's body was later found in the water. A post-mortem examination was being held to discover whether he drowned or died of his injuries Police are withholding his identity until a formal identification has taken place but he is believed to be from the Brighton area.

A second man, in his 50s, who suffered serious internal injuries and a suspected broken leg, is off the critical list and is in a stable condition in hospital.

Police said three people on one boat and four on the other all knew each other. Some were related, others were friends. No one else was injured.

Peter Baker, deputy district controller for Solent Coastguard, said: "This appears to be a tragic accident which has marred a busy weekend of marine leisure along the coast."

Sean Bagnall, from London, who was on the pier with his wife, Andrea, said: "It looked like they just got too close and one bounced off the other. It happened in a split second."

It is believed the brother of the missing man, who was on the boat with him, joined the search.

When the body was found he was taken to hospital suffering from shock.

Neither boat sank in the crash. Both have been taken to Brighton Marina for examination by accident investigators.

Shoreham lifeboat spokesman Dave Casson said: "It seems these people were out messing around enjoying themselves when they hit each other."