POLICE are treating the deaths of a toddler and a man, who fell from a bridge early this morning, as a murder-suicide.
Police said the man, thought to be the child's father, rode his bike over the footpath on the outbound side of  Brisbane's Story Bridge.

It is thought he threw the child over the safety rail and then jumped.

It is understood the man was aged 40, and the boy just two-years-old.

Police said they did not believe the child was subject to a custody battle of any kind and added the next-of-kin had been notified.

A man walking across the Story Bridge had this morning reportedly alerted police to the deaths.

The man found the pair just after 3am.

LNP leader Campbell Newman extended his condolences to the family, describing the event as "just absolutely awful".

But he refused to be drawn on whether safety improvements were needed on the bridge

.

"I think this is just a terrible thing and my heart goes out to the family and relatives and that's all I can say today," he said.

"Let's find out what's really happened here."

Earlier, The Courier-Mail reported that detectives and uniformed police were scouring the area of parkland below the bridge following the tragedy.

Police used a screen for privacy as they loaded the two bodies into a silver van.

Scientific police also dusted for fingerprints on the outbound footpath of the Story Bridge and cordoned off a mangrove area in the search for clues.

This is the third security incident in the last year at the Story Bridge.

A woman jumped to her death after murdering her teenage daughter in September 2011.

Two months later a father also caused traffic chaos when he scaled the bridge to protest over personal issues.

The incidents have prompted frustrated residents to call for safety screens across the bridge where pedestrians walk to prevent more people from falling and jumping

.

Police data show up to one suicide happens every three weeks at the West Gate Bridge. A 2004 coroner's report recommended anti-suicide fencing or barriers be erected on the bridge to deter people from taking their lives.

In 2008, the bodies of a mother in her late 20s and her 18-month-old baby were found on the river bank below the West Gate Bridge, prompting further calls to erect a suicide barrier.

Those who argue for a suicide barrier claim that most of those who jump from the West Gate Bridge do so through impulse and that police officers who try to save those who try to jump are putting their own lives in danger.

There are multiple incidents of police officers dangling off the side of the bridge while holding onto would-be jumpers.

A 2000 Royal Melbourne Hospital study on people who jumped from the bridge found at least 62 cases between 1991 and 1998. Seven people survived the 58-metre fall. Seventy-four percent of those who jumped from the bridge were male, with an average age of 33. More than 70 percent were suffering from mental illness.

Of those who jumped off the West Gate Bridge, 31 percent fell on land. Some of those who land in water drowned afterwards.

In 2008, Melbourne girl, Darcy Freeman, was thrown off of the bridge by her father and later died in hospital.
She was only 4 years old. Her father, Arthur Freeman, was subject to a custodial order and was deeply disturbed by the verdict.
In April 2011, Freeman was found guilty of murder and sentenced to life in prison.

In February 2009 the first stage of a temporary suicide barrier was erected, constructed of concrete crash barriers topped with a welded mesh fence. By June that year it has been claimed that the fence has prevented two suicides.

Most of the second stage of the barrier has been completed throughout the span of the bridge. The barriers are costed at $20 million