A string of cruel coincidences led to the death of a two-year-old boy in a lake after he wandered off from a mother-and-toddler session.

Alexander Harvey Clark was found drowned in a lake after his mother turned her back for "seconds", an inquest heard.

He was playing Whizzkids at Littlehampton Leisure Centre when his mother Nasrin Clark noticed he was missing.

The toddler was found face-down in a boating lake in nearby Mewsbrook Park following a frantic search by his mother and staff.

Mrs Clark told Arundel Coroners Court yesterday she only took her eyes off her son, who had a fascination with water, for a few seconds before realising he had vanished.

The inquest heard how outer doors to the area of the leisure centre complex, called the Dome, may have been left open, allowing Alexander to wander off.

Mrs Clark, a nursery teacher of Grandville Road, Littlehampton, said the doors were very stiff and, in her opinion, could not be opened by a two-year-old.

She said: "Alexander was very sociable, very active and quite independent. He could walk very well. He was very inquisitive.

"During the morning I was watching him all the time. Alexander was very well that morning and as active as usual and enjoying the session.

"I was talking to Anita Lamprall, who was covering for the Whizzkids' usual monitor, about our coming holiday in France. I looked at her for a few seconds and when I turned back he had gone. I panicked.

"He liked playing with water so I thought he might have been playing with taps in the toilet."

Mrs Clark described her son's fondness for water after many seaside visits.

Mrs Lamprall, who was in charge of the group on June 21, said: "I remember while I was speaking to Mrs Clark she kept eye contact with me, which at the time I thought was odd.

"I have a young son and I know as a mother when you have a child you're always looking for them and you feel rude when talking to someone."

Mrs Clark began checking the centre and the area outside and was quickly joined by other mothers.

One mother, Margaret Irvine, walked down to the boating lake, about 125 metres from the playgroup, and spotted Alexander in the water.

Mrs Lamprell said she had overall control of the group but was not responsible for individual children.

She told the inquest it was her first time in charge and she had no formal training for leading such sessions.

She said some mothers hooked open the outer doors to push prams through and might have left them open.

Coroner Roger Stone asked Mrs Lamprell: "If the doors were hooked back, they would not be checked as to whether they were open of shut?"

Mrs Lamprell said: "I would not want to leave the area because I am there to oversee the safety of the children."

Coroner Roger Stone said how Alexander got outside was a "missing piece of a jigsaw puzzle".

He said the events leading to his death were a string of "cruel coincidences".

CCTV footage examined by police did not throw any light on how he got out.

Detective Inspector Paul Williams, who led an investigation, ruled out gross negligence by the leisure centre staff, employed by Arun District Council.

But he made a list of measures he felt may have made it harder for a child to wander from the Dome.

He said: "Yes, his death could have been prevented but it was the combined aspect of the what ifs that caused his death."

His recommendations included more secure outer doors with handles further from the ground, a clearer search procedure if a child disappeared and clearer guidance over the extent of parental responsibility.

He said: "It would be my best guess the doors would have been open, based on the pressure required to open them and the accounts of other parents.

"It is impossible to say if any measures would have prevented this tragedy".

A post-mortem confirmed Alexander had drowned and ruled out any harm being inflicted on him before his death.

The jury returned a verdict of accidental death.