Valentine tweet by Oscar Pistorius' girlfriend

Hours before paralympian Oscar Pistorius allegedly shot dead his girlfriend Reeva Steenkamp, she posted a Valentine's Day tweet.

It read: "What do you have up your sleeve for your love tomorrow???"

Pistorius is renowned worldwide for his achievements on the sports field, but his love life has been equally headline-worthy.

Pistorius, 26, was born without fibula and had both legs amputated below the knee before he was a year old.

He shot to fame in 2008 when he won a case at the Court of Arbitration for Sport, which cleared him to run against able-bodied athletes.

He was dubbed "Blade Runner" because of the futuristic metal legs he used to compete in races.

Pistorius was in police custody on Thursday following a shooting of a woman at his Pretoria home on Wednesday night. She was identified as girlfriend and FHM model Reeva Steenkamp.

Shiri Reouveni, of Steenkamp's PR agency, said they had been told it was Steenkamp who had been shot, but did not want to say more.

Before Pistorius attained star status, he was attached to girlfriend Vicky Miles, who had known him since his school days. A photo of them in 2006 shows Miles on his lap, both of them beaming.

They split up in 2008 and re-united a while later. They apparently broke up again in early 2012.

In mid-2012, the New York Post suggested Pistorius had moved on from Miles and was dating Russian supermodel Anastassia Khozissova. The leggy blonde was said to have met the athlete in New York and they were spotted holding hands in Chelsea.

Neither of their public relations teams confirmed the relationship.

Cape Town marketing student Samantha Taylor told the City Press newspaper in November 2012 that she had been dating Pistorius for a year-and-a-half.

She and Oscar were filmed on the beaches of the Seychelles on SABC3 magazine show Top Billing in September 2012.

Pistorius arrived at the SA Sports Awards in November with FHM model Reeva Steenkamp. She was quoted in the City Press newspaper as saying at the event: "We're just friends. I promise I'll tell you if there's anything more... It's just a coincidence that we're sitting at the same table and arrived in the same car".

Taylor first told City Press that Steenkamp was dating Pistorius's friend.

She then claimed Steenkamp had been following her on photo-sharing site Instagram and knew exactly where she was and everything that was happening in her relationship with Pistorius.

"Oscar has such a way with women. She's probably not the only one he's got," Taylor reportedly said.

She confirmed they had split.

In an interview with Rapport newspaper, Taylor said she "prepared to reveal what Pistorius made me go through", but later withdrew everything she said in a lawyer's letter.

The Star newspaper then reported in late November that Pistorius and Clifton Shores TV producer Quinton van der Burgh came to blows about the alleged infidelity of an unnamed 18-year-old woman Pistorius was dating.

The athlete was said to have confronted Van der Burgh at the Kyalami racetrack in Johannesburg. Van der Burgh laid a charge of intimidation against him.

The two men exchanged threats via sms. Van der Burgh's friend, former soccer player Marc Batchelor, then got involved in the spat. Pistorius allegedly told Batchelor he would break his legs.

Batchelor then apparently threatened Pistorius.

Pistorius made history when he became the first amputee to win a silver medal at the World Athletics Championships in 2011.

The following season he secured two more silver medals, in the men's individual one-lap sprint and the relay event, at the African Athletics Championships in Benin.

Pistorius again wrote himself into the history books when he became the first amputee to compete on the track at the able-bodied Olympic Games in August 2012.

Pistorius reached the semifinals in the individual 400m event, and also competed in the relay final, with South Africa given a free pass after they were obstructed by the Kenyan team in the heats.

A six-time Paralympic Games gold medallist, the Blade Runner holds the men's 100m, 200m and 400m world records in the T44 disability class.