Man claims he saw Joanne Ratcliffe and Kirste Gordon loaded into van at a boarding house after their disappearance from Adelaide Oval Robert McMahon thinks he witnessed an abduction, holding two sketches he said he did of the girls on August 15, 1973. Picture: Dylan Coker Source: News Limited MAJOR Crimes detectives are investigating claims that Joanne Ratcliffe and Kirste Gordon were loaded into the back of a van at a Prospect boarding house soon after disappearing from Adelaide Oval 40 years ago. Prospect man Robert McMahon, 73, approached the Sunday Mail during the week claiming he saw the girls at a Vine St boarding house on the day they were supposedly abducted from the 1973 SANFL match between Norwood and North Adelaide. He said the girls were accompanied by a man known as 'Scotty' with whom he shared the boarding house. He said Scotty, who claimed the girls were his grandchildren, paraded the pair in front of his housemates before taking them outside and ordering them into a cream-white van parked in a laneway at the back of the boarding house. READ MORE: Police seek help Oval abductions case Mr McMahon said he was so disturbed by the incident he drew pictures that night of what he claims he saw and wrote a letter detailing what happened at the property on August 25, 1973. Robert McMahon holding sketches of Joanne Ratcliffe and Kirste Gordon. Picture: Dylan Coker The artist said he kept the sketches and letter in a box before later placing them in a sealed envelope. He opened the envelope in front of the Sunday Mail this week and produced sketches that appear to be accurate portrayals of Joanne, 11, and Kirste, 4. There are also drawings of Scotty and a cream white van along with two scribbled notes. Major Crime detectives collected the documents on Friday and intend to interview Mr McMahon this week. Mr McMahon claims that late on the afternoon of August 25, 1973 he was sitting in his room watching a VFA football match on TV when he "heard a racket" out the back of the house. Joanne Ratcliffe and Kirste Gordon disappeared at Adelaide Oval in 1973. "I went to check and there was one of the borders coming in and he had two children with him," he said. He had the little one under his right arm and the other one was ahead of him. He walked them around in a circle in front of us (four or five men) laughing and joking. He said the kids were his grandchildren but when the older one went to speak he told her to 'shut up' and not say anything. I can still see the taller girl now as she walked passed me. It was all very weird, Mr McMahon, who was 33 at the time of the girls' disappearance, went to the kitchen area of the boarding house where he said he watched the man drag the small girl to the back of his van that was parked in a laneway. "He threw the little one in roughly and motioned to the bigger one to jump in," he said. He slammed the back door and then locked it. It's not the way you treat your grandchildren. Mr McMahon said he was so concerned he returned to his room and did sketches of the girls, Scotty and the van. He said he rang police the next day when news broke of the possible abductions. "When I saw the photos I knew for sure it was those girls that I'd seen." he said. But the police said they had hundreds of sightings and would get back to me. He claimed they never did. He said he rang police a week later and then again around the first anniversary of the abductions with the same result. He said he didn't pursue it further out of frustration. But he contacted the Sunday Mail this week after reading a story published in the paper last weekend, marking the 40th anniversary of the girls' mysterious disappearance. Mr McMahon said Scotty - he never knew his real name - did not return to the boarding house and he never saw him again. He described Scotty as being in his early 40s, with a broad Scottish accent. He said he was about 165cm, had grey receding hair and limped on his right side. Former Adelaide Oval assistant curator Ken Wohling reportedly saw the back of a man walking with the two girls and noticed he had a 'stoop'. Mr McMahon, raised in a Catholic orphanage in Geelong, said he was fully aware of the pain and distress his story could cause if he was lying. "I will tell the same story on my death bed and if I ever get to face my God," he said. I have a bit of guilt that I didn't try even harder at the time to get it out but we all have things we have to live with and I did try.