The National Prosecuting Authority (NPA) has refused to enrol the case against seven security guards at the Lindela Repatriation Centre in Krugersdorp accused of aiding in the escape of 37 illegal immigrants, due to insufficient evidence.In a statement on Tuesday, NPA spokesperson Phindi Mjonondwane said the matter was not placed on the court roll and that the docket has been sent back to police with instructions for further investigations that must be conducted. "Once those investigations are concluded, the docket will be brought back to the National Prosecuting Authority for a decision," Mjonondwane said. READ | 37 illegal immigrants escape from Lindela Repatriation Centre, Motsoaledi claims 'inside job'News24 reported on Friday that the seven security guards were arrested after handing themselves over to police, but were later released on a warning to appear in court. The accused were facing charges of aiding persons to escape. Two other guards, who have also been implicated, had not handed themselves over, police said on Friday. It is alleged that on 3 May the guards – who are contracted to a private security firm – colluded with the foreign nationals being held at the centre to help them escape.Lindela Repatriation Escape: Suspended security guards heading to the CCMA | @Sesona_Ngqaks https://t.co/L0pmY1Paqt pic.twitter.com/nc4eEW1589— News24 (@News24) May 11, 2020 Home Affairs Minister Aaron Motsoaledi told the media that 37 foreign nationals, who were in the country illegally, managed to escape after being helped by security guards, who were in the middle of a dispute with their employer. "This escape is an inside job. I can assure you it's an inside job," Motsoaledi said.READ | Seven guards arrested for allegedly helping 37 illegal immigrants escape repatriation centreHe said the squabble between the employees and their employer led to security guards knocking off from work at 14:00 instead of 17:00."They (the escapees) were tipped off by guards that they would be leaving early and that they could do what they want."The escapees then allegedly climbed through the ceilings, before scaling the walls. Motsoaledi said the security guards present were overpowered because the other guards had left early.