Oscar Pistorius is the athletics golden boy who likes to thank God and kept a pistol by his bed and machine gun ready at a window.

Now he is charged with murder after his girlfriend, model Reeva Steenkamp, 30, was found shot dead at his home yesterday.

Only last November, Pistorius, the double-amputee sprinter known as the "Blade Runner" and feted the world over as an inspiration for his Olympic and Paralympic efforts, tweeted about how he had gone into "full combat recon mode" after mistaking his washing machine for an intruder.

Tweets in recent months appear to paint the picture of a happy couple.

Quoting a tweet from Reeva Steenkamp on December 6, "Wondering what my stalker is up to? Kinda miss him lurking around 2nyt".

Pistorius replies: "Heard he is taking a water break with the boys!;)"

Steenkamp gushed over Pistorius on Twitter, seeming to relish going out with one of South Africa's biggest stars.

In a recent interview Steenkamp, a regular on the South African party circuit, described Pistorius as having "impeccable" taste.

"His gifts are always thoughtful," she was quoted as saying.

Some of her last Twitter postings indicated she was looking forward to celebrating Valentine's Day on Thursday with him.

"What do you have up your sleeve for your love tomorrow???" she posted.

However, police investigating the case say they were aware of previous incidents at the house of a "domestic nature", and recent media interviews with Pistorius revealed he kept an assortment of weapons in his home.

"Cricket and baseball bats lay behind the door, a pistol by his bed and a machine gun by a window," Britain's Daily Mail wrote in a profile published last year.

In November 2011, Pistorius tweeted about going to a firing range, boasting: "Had a 96% headshot over 300m from 50shots! Bam!"

He was arrested in 2009 for assault after slamming a door on a woman and spent a night in police custody. Family and friends said it was just an accident and the charges were later dropped.

With his arrest and charge, Pistorius went from podium to police cell.

At the London Olympics in August, Pistorius reached the finals of the 4x400 metre relay and semifinal in the 400m sprint, with his carbon fibre blades clattering into the history books.

But the script didn't go to plan when the Paralympics started later in the month.

The 100m and 200m titles were lost in a blaze of fury as he became embroiled in a public row with the rival he accused of unfairly using lengthened blades to win the 200m.

Only in the final event, the 400m, did Pistorius finally collect an individual gold.

While his carefully honed public image – as the poster boy for Paralympic sport – was a little tarnished by his outbursts, Pistorius has spent the time since then, on Twitter in particular, displaying the softer side that enthralled sports fans and the general public alike.

"Don't sweat the small things and chase your aspirations," he tweeted on January 29, while posting an image of a quote from Walt Disney: "All our dreams can come true, if we have the courage to pursue them."

At the start of December he retweeted a series of motivational messages.

"Life consists not in holding good cards, but in playing those cards you hold well."

And from Oscar Wilde: "A gentleman is one who never hurts anyone's feelings unintentionally."

Displaying his religious side, Pistorius peppered his timeline with references to his faith, including: "God is good all the time, all the time God is good!"

As he prepared to see in 2013, Pistorius wrote: "Had a blessed day today. Grateful for the type of people I have in my life."

But his Twitter timeline more regularly featured self-portraits sunning himself or posing among the great and the good at conferences or glitzy events.

In his last personal tweet on February 11, Pistorius was looking forward to the launch of his foundation in July to help 10 disabled children.

It was a reminder of how Pistorius had overcome difficulties since having both legs amputated below the knee in the first year of his life.

- Agencies