Internet phishing scammers are targeting fans of Oscar Pistorius with bogus Facebook pages that solicit public donations to fight the murder charge against him.

The latest such con appears on a profile purporting to be that of Carl Pistorius, the athlete's older brother, and has been condemned by his family, who are seeking to shut it down.

Pistorius, on trial for shooting dead his girlfriend Reeva Steenkamp, is undergoing a 30-day mental evaluation at a psychiatric hospital in Pretoria, South Africa. As the case drags on, he has been forced to sell his house to meet spiralling legal bills.

According to South Africa's Star newspaper, the fake Facebook page, which includes a photo of Carl, states: "We seek financial support for the trial, debts and pending projects we have at hand. If you are interested in working actively with us in this direction, please do contact: Mrs Victoria Anderson at vicandersonl@hotmail.com."

The page's most recent wall post read: "Thank You all for the continued support and words of encouragement during this difficult time. Pray for Oscar."

The owner of the vicandersonl@hotmail.com account did not respond to an email sent on Wednesday.

Anneliese Burgess, a spokesperson for Pistorius, told the Star that people responding to the scam were asked to rendezvous in Sunnyside in Pretoria to talk about potential investments. She warned against going to such a meeting.

"The family has made it clear that anyone soliciting money on their behalf are doing so fraudulently," she was quoted as saying. "We will, once again request Facebook to shut this profile down. All the legitimate Pistorius family members' Facebook pages are either deactivated or set on full privacy settings."

In March, when the trial began in the glare of the world's media, a sham Facebook page called "Oscar Pistorius Official" tried a similar con trickand was eventually shut down. Fraudsters also used Twitter to redirect people to a false account.

Members of Pistorius's family are known to be concerned about the escalating costs of the trial. His legal team includes three of South Africa's leading defence lawyers, a number of ballistics and forensic experts and, media reports say, an American crime scene reconstruction company. The total cost has been estimated at £5,400 a day.

The Paralympian has meanwhile lost lucrative sponsorship deals because of the case. Last month his estate agent announced that he had sold the luxury home, valued at more than £280,000, where he killed Steenkamp, a model and law graduate.

Pistorius denies murder, insisting that he panicked because he thought he heard an intruder. He was admitted as a day patient by the Weskoppies hospital following an order by judge Thokozile Masipa after a defence expert witness testified that the 27-year-old has generalised anxiety disorder (GAD).

South African media reported this week that the psychiatrist's suggestion has caused panic among the disorder's sufferers. The Sunday Times quoted Cassey Chamber, director of the SA Depression and Anxiety Group, as saying it had received "hundreds of calls" from people concerned that having the disorder could lead to "unpredictable, unstable and violent" behaviour.

"We have had people asking if their loved ones with GAD need to be hospitalised immediately."

She added: "Anxiety is an introspective issue and sufferers of GAD are highly unlikely to be dangerous to others."

Pistorius's trial is due to resume at the high court in Pretoria on 30 June.