A woman suspected of driving her car and a 15-month-old girl on to a public beach in West Sussex before trying to strangle the youngster with seaweed is in custody on suspicion of attempted murder, police said.
The 35-year-old woman was being questioned by police as doctors examined the toddler who was plucked to safety from the beach by coastguards.
A source close to the inquiry said the woman "smashed up" her Volkswagen Golf car before driving it off Selsey Bill and on to the beach packed with sunbathers.
The woman and youngster then disappeared before police found her attempting to strangle the child with strands of seaweed.
It followed a frantic two-hour search this afternoon by Sussex Police officers, assisted by the police helicopter, and Solent Coastguard who scoured the coast in the Selsey area.
The woman's damaged car was found on the beach where it was thought to have crashed through a wall from a main road. No one was hurt on the beach.
A Sussex Police spokesman said the woman was arrested on suspicion of attempted murder. The child was being cared for at St Richard's Hospital in Chichester.
It was not clear if the woman was the girl's mother, but it was understood the two are related.
The spokesman said: "We do not know yet if the baby was injured.
"Police are now appealing to people on the beach who may have witnessed the incident to contact police".