Opposition parties have called on the public protector to widen the investigation into the Gupta family' s business interests after the Sunday Times reported on claims that they had sought to procure a R51-billion Passenger Rail Agency of SA tender . DA transport spokesman Manny de Freitas said the investigation should be as "holistic as possible."He also questioned Prasa's internal investigation, saying the rail agency was "effectively referee and player."EFF national spokesman Mbuyiseni Ndlozi said: "Our conviction is that for as long as [Jacob] Zuma is president, the country will consistently fail.The Guptas' R51bn train grabSensational new allegations of how the Gupta family and President Jacob Zuma's son Duduzane tried to capture a parastatal and profit from a multibillion-rand tender have emerged. "Saving of our country relies on more than [the public protector's] investigation."The public protector is currently investigating tenders and licences awarded to the Gupta family as well as allegations that they have unduly influenced government appointments.Public protector spokesman Oupa Segalwe said he was unaware of the probe being expanded.COPE spokesman Dennis Bloem said: "More than 75% of the country no longer believes that the ANC is capable of tackling the issue of state capture."Guptas deny R51bn train grabClaims that the Guptas attempted to capture a R51bn Passenger Rail Agency of SA (Prasa) tender on behalf of a bidder in 2012 are among many allegations that are “completely unfounded”. He said ANC officials should sign sworn affidavits that they have never acquiesced to an "egregious business deal" prompted by the Guptas or the Zumas."Those who have something to hide will show themselves by ducking and diving."..